The South African species of Hemizygia ( Lamiaceae )

The South African species o f Hemizygia are reviewed and 28 species are recognized, including the following new names: H. macrophylla (Guerke) Codd (=Syncolostemon macrophyllus Guerke), H. pretoriae Guerke var. heterotricha Codd, H. cinerea Codd, H. incana Codd, H. modesta Codd, H. parvifolia Codd, H. punctata Codd and H. ramosa Codd.


IN T R O D U C T IO N
Hemizygia was initially proposed by Bentham as a section of Ocimum in DC., Prodr. 12:41 (1848), to accommodate the single species O. teucriifolium Hochst., in which the filaments of the lower (anticous) pair of stamens are fused at the base, in contrast to the free filaments of typical Ocimum species.Briquet raised the section to generic rank in Pflanzenfam. 4,3a:368 (1897) and subsequently described several species.He laid stress on the fused filaments of the anticous stamens, in which respect it resembled Syncolostemon E. Mey.ex Benth., but differed from the latter in the broadly ovate upper tooth of the calyx.
Baker in FI. Trop. Afr. 5:365 (1900) and N. E. Brown in FI.Cap. 5 ,1 :237 (1910) included Hemizygia in Orthosiphon, the latter author pointing out that the union of the filaments may vary in some species and even on the same plant.
Ashby in J. Bot. Lond. 73:312, 343 (1935) resus citated the genus Hemizygia, remarking that although the degree of union of the filaments varies, only very rarely are they free to the base.He also noted other differences in the androecium of Hemizygia and Orthosiphon.The anticous pair o f stamens in Hemizygia are contiguous at their insertion at the mouth o f the corolla tube, while in Orthosiphon they are well separate at their insertion, which is at a short distance within the corolla tube, or rarely in the throat.The posterior stamens are inserted from about the middle to near the base of the corolla tube in Hemizygia (with one exception, H. gerrardii) and are well exserted (with the exceptions of H. pretoriae and H. persimilis), while in typical Orthosiphon the upper stamens are inserted near the throat and are only shortly exserted.It may also be noted that in Hemizygia the filaments are usually pubescent in the lower part, but in typical Orthosiphon they are glabrous.
He also drew attention to certain differences in corolla structure between the two.In Hemizygia the corolla tube is usually dilated at the throat and truncate at the m outh; the posterior lip is small and the anterior lip larger and often deflexed at maturity In contrast, typical Orthosiphon rarely has the corolla tube widened at the throat, the mouth is not truncate but the two lips meet laterally and are about equal in length.He concludes that the exceptions are suffi ciently few that they should not necessitate the merging of Hemizygia in Orthosiphon.
This view is supported in the present study and reference may be made to my review of the South African Orthosiphon species in Bothalia 8:149 (1964).
Here it was noted that the species separated by Bremekamp in his genus Nautochilus, together with those of Orthosiphon sect.Serrati Ashby, form an aberrant group, which was placed as Orthosiphon subgen.Nautochilus (Brem.)Codd.In these species the filaments of the posterior stamens are attached near the base of the corolla tube and are pubescent, as in Hemizygia, while the anterior filaments are free to the base, as in Orthosiphon.The corolla shape in these species, although somewhat intermediate, agrees better with Orthosiphon than with Hemizygia.
Differences between Hemizygia and Syncolostemon must also be found if the former genus is to be upheld, and these are discussed in another article (Bothalia 11: 21 1976).The corolla and androecium characters are virtually the same in the two genera and it is mainly the calyx which provides a basis for distin guishing them.In Hemizygia the upper calyx tooth is broadly ovate and decurrent on the tube while the lower 4 teeth are usually subulate to spinescent; in typical Syncolostemon, on the other hand, the calyx is subequally 5-toothed.Two intermediate species were noted in which the upper tooth was elliptic or broadly elliptic, not decurrent on the tube.These were included in Syncolostemon because of their close affinity with S. rotundifolius and S. densiflorus.
Orthosiphon, Syncolostemon and Hemizygia form a closely related series of which Orthosiphon (1830) is the oldest name.The great majority of species can be allocated without great difficulty to one of the three genera now upheld and this appears to be sufficient justification for continuing with their present circumscription.
A striking feature of some Hemizygia species is the strong development of the apical bracts of the inflorescence into a persistent colourful tuft or com a.
(upper pair included in H. pretoriae), didynamous; Orthosiphon sensu Bak. in FI. Trop. Afr. 5: 365 upper pair affixed about or below the middle of the (1900), partly; sensu N.E. Br. in FI. Cap. 5     patches of white tom entum ; verticillasters 3-6-Soft shrub 1-1,5 m tall, branching from the base, flowered, up to 2 cm or more apart.C a l y x 7 mm long, highly arom atic; stems several, woody at the base, glandular-hispid, setose in the throat, becoming arising from a perennial woody rootstock, sparingly swollen and narrow at the m outh when in the fruiting branched, leafy towards the base, densely grey stage; upper lip ovate, acuminate, 2 mm long: lower pubescent.L e a v e s shortly petiolate; petiole up to 4 teeth deltoid-subulate, 2 mm long.C o r o lla purple, 4 mm long; blade ovate-lanceolate to lanceolate, 17-18 mm long, pubescent on the lobes; tube 11-6-9 cm long, 2 ,5 -3 cm broad, both surfaces densely 12 mm long, widening to 5-6 mm at the m outh; and coarsely stellate-velvety, tending to fold along upper lip a small appendage, 1 mm long; lower lip the midrib and then somewhat falcate; apex acute, concave, 5-6 mm long, horizontal.S ta m e n s exserted well beyond the lower lip, curled upwards; upper pair attached below the middle of the corolla tube, puberulous near the base; lower pair united to near the apex.Stigma bifid.
Recorded from the foothills of the Drakensberg in northern Natal and southern Transvaal, in dense grass, often among dolerite rocks, at altitudes from 1 500 to 1 800 m.Flowering is mainly from January to April.Distinguished from all other species by the large leaves covered on both surfaces with a dense, coarse stellate pubescence and by the large, laxly branched inflorescence.Its nearest affinity is probably with Syncolostemon parviflorus but the upper calyx tooth is broadly ovate.It is, therefore, somewhat inter mediate between Hemizygia and Syncolostemon.
Grows with bracken and shrub on stony hillsides and forest margins at altitudes of 1 400 to 1 800 m in north-eastern Transvaal.A distinct species easily separated from others with stellate pubescence by the large, petiolate leaves.With its large purplish bracts and mauve-pink flowers, this is a showy species which grows well under humid conditions but has not succeeded in cultivation in the drier parts o f the Transvaal.
Known only from three gatherings near The Downs in north-eastern Transvaal, where it apparently grows at forest margins.A small-leaved species related to the two species described below, H. parvifolia and H. cinerea.From H. parvifolia, which also has 2-flowered verticillasters, it differs in the longer, more lanceolate-elliptic leaves and the larger apical bracts; H. cinerea also has small bracts and 6-flowered verticillasters but the leaves, which are similar in shape to H. rugosifolia, are finely grey velvety pubescent on both sides.
H. rugosifolia is a little known species last collected in 1945.
Type.Found among quartzite rocks at altitudes of 1 300 to 1 500 m on the eastern Transvaal Drakensberg escarpment; in flower from October to March.

H.
parvifolia is a much-branched shrub up to 1 m tall, related to H. rugosifolia Ashby, a species known as yet only from The Downs, grid 2430 (-AA), some 100 km to the north-west of Blyde River Gorge, on the same escarpment.H. parvifolia may be separated on the basis of the smaller, more broadly ovate leaves, the grey indumentum of the underside of the leaves, the smaller inflorescence which is simple or sparingly branched, the shorter bracts and the presence of stellate hairs on the calyx.
It would be interesting to know whether either species or intermediates occur on the escarpment between The Downs and Blyde River Gorge.This is a relatively inaccessible area which is scarcely known botanically.Further study is also required of the escarpment between the Blyde River Gorge and the other known locality on the Nelshoogte Forestry Station near Kaapsche Hoop.

H.
incana is related to H. rugosifolia Ashby but may readily be distinguished by the dense grey-white tomentum on both surfaces of the leaves, obscuring the veins, the smaller and more pubescent bracts and the villous calyx.For differences between this species and H. cinerea Codd, described below, see notes at the end of the latter description.
Found at altitudes of 1 700 to 2 300 m in the N atal Drakensberg between Mont-aux-Sources and Cathkin Peak where it is a common shrub along stream banks, at the foot of cliffs, and on mountain sides.It flowers mainly from December to April.The few specimens of this species which Ashby had at his disposal were confused with //.elliottii (Bak.)Ashby and //.stenophylla (Guerke) Ashby, and those specimens with entire leaf margins would tend to run to H. elliottii in his key.However, H. elliottii differs in having ovate-lanceolate leaves and a capitate stigma, while the calyx is stellate-pubescent, not villous as in H. cinerea.H. elliottii is essentially a plant of hot, dry savanna country, extending from Rhodesia to Botswana and to the western, northern and eastern Transvaal lowveld, but does not enter Natal.
H. stenophylla, on the other hand, has linearlanceolate leaves with somewhat thickened and inrolled margins and colourful lanceolate bracts 12-15 mm long, while the calyx is glandular-hispid, also lacking the villous hairs possessed by H. cinerea.H. stenophylla occurs well to the south of H. cinerea and at lower altitudes, from the Transkei to southern Natal.
H. cinerea is probably more closely allied to the two Transvaal species, H. rugosifolia Ashby and H. incana Codd (described above).From H. rugosifolia it differs in the dense tomentum on both surfaces of the leaf, the smaller bracts and the villous calyx.From H. incana it can be distinguished by the smaller leaves, which are usually dark grey on the upper surface and which are often entire or toothed only in the upper half, while the flower parts (calyx, corolla and stamens) are smaller.H. cinerea is known only from the Natal Drakensberg between Cathkin Park and Mont-aux-Sources, while H. incana appears to be restricted to the Kaapsche Hoop area in the eastern Transvaal.

7.
Hemizygia elliottii (Bak.)Ashby in J. Bot. Lond. 73: 345 (1935), pro parte excl.Natal spec.Type: Matabeleland, Elliott s.n.(K, holo.).Soft shrub 35-60 cm tall, woody at the base; branches stellate-tomentose.Leaves subsessile to shortly petiolate; blade lanceolate to ovate, 15-25 mm long, 4-12 mm broad, densely stellate grey velvety on both surfaces; apex acute, base obtuse; margin entire.Inflorescence simple or occasionally with a pair of branches near the base, 6-12 cm long; rhachis densely and shortly stellate-tomentose; bracts broadly ovate to subrotund, persisting as a dense mauve-purple coma, 7 -1 1 x 5 -8 mm, stellate-pubescent near the truncate base, apex rounded; verticillasters 2-6flowered, up to 12 mm apart.Calyx 5 mm long, sparingly stellate-tomentose mainly on the tube; upper lip subrotund, rounded at the apex, 2 mm long, markedly decurrent on the tube: lower 4 teeth deltoidsubulate, up to 2 mm long.Corolla white to pale mauve, 13 mm long, glabrous; tube 9 mm long, widening to 3 mm at the throat; upper lip a small appendage 1 mm long; lower lip concave, 4 mm long, often deflexed.Stamens shortly exserted, not or only slightly exceeding the lower corolla lip; upper pair attached about the middle of the tube, filaments pubescent for about two-thirds their length; lower pair attached at the throat, adhering loosely at the base for a few mm.Style capitate.

Orthosiphon elliottii
Found in dry, subtropical woodland in western, northern and eastern Transvaal, at altitudes of 300 to 1 300 m, often on red sandy loam soil; also in Botswana and Rhodesia.Collected in flower between October and April.Superficially similar to H. cinerea Codd but the small grey leaves are usually broader and the margins are always entire.It is, however, not closely related to H. cinerea because the stamen filaments are pubescent to well above the middle (this can often be seen on dried specimens without dissecting the flowers), the stigma is capitate and there is a coma of colourful bracts at the apex of the inflorescence.
An interesting variation is found in the numbers of flowers produced per verticillaster.Normally a constant character for a species, two series are found in H. elliottii.In all specimens from Rhodesia, Bot swana, western and northern Transvaal, the verti cillasters are 2-flowered, while the specimens from the eastern Transvaal lowveld have 6-flowered verti cillasters.As no other difference can be found it is not proposed to accord separate rank for the latter form.

Orthosiphon stenophyllus
Inflorescence simple or with one or two pairs of branches near the base, 8-18 cm long; rhachis glandular-hispidulous often with some branched hairs; bracts persisting as a colourful coma, lanceolate to ovate-lanceolate, 10-15 mm long, acute, mauve to purple, stellate-tomentose; verticillasters 4-6flowered.Calyx 7-8 mm long, glandular-hispidulous; upper lip ovate, rounded, 3 mm long, decurrent; lower 4 teeth subulate to bristle-like, the lowest pair the longest, up to 4 mm long.Corolla pale mauve to rosy-mauve, 13 mm long, glabrous except for the lips; tube 10 mm long, widening to 3 mm at the throat; upper lip a small appendage; lower lip concave, 3 mm long, often deflexed.Stamens exserted by 10 mm, well exceeding the lower lip; upper pair attached about the middle of the tube, filaments pubescent in the lower part; lower pair attached at the throat, filaments united to or near the apex.Stigma minutely bifid.
Found in dense grassland often near forest and among rocks in southern Natal and East Griqualand.Flowers mainly from January to March.Resembles H. rehmannii (Guerke) Ashby from the north-eastern Transvaal but has slightly narrower, more lanceolate leaves and a tuft of conspicuous mauve-purple bracts at the apex of the inflorescence.
Although it has been confused with the species now described as H. cinerea Codd, the latter tends to have more elliptical leaves and also lacks the coma of colourful bracts.Although both occur in Natal, H. cinerea occurs further to the north and at higher altitudes, between Cathedral Peak and Mont-aux-Sources.

Orthosiphon rehmannii
Occurs usually in shallow sandy soil among rocks in grassland, often near forest margins, from Woodbush to The Downs in north-eastern Transvaal, at altitudes o f 1 500-2 000 m. Flowering is mainly from January to M arch.Its affinity with H. stenophylla is discussed under that species.From H. cinerea, a N atal species which also has small, inconspicuous bracts, it differs in the leaves being rather more rugose above and usually greyish-yellow below, and the larger corolla, which is only 8-11 mm long in H. cinerea as against about 17 mm long in H. rehmannii.
12. Hemizygia subvelutina (Guerke) Ashby in J. Bot. Lond. 73: 346 (1935).Type: Lydenburg, near Paarde Plaats, Wilms 1152 (BM, K).Bushy herb or soft shrublet 20-50 (-80) cm tall, branching from the base; branches few to many from a perennial woody rootstock, erect or ascending, sparingly branched, densely beset with leaves and short leafy shoots, densely stellate-pubescent, often with a yellowish tinge.Leaves sessile, usually ericoid, linear to linear-lanceolate, 5-10 (-15) mm long, 1-2 (-5) m m broad, coriaceous, stellate-scabrid above, usually yellowish stellate-tomentose below; margin revolute, entire.Inflorescence simple, 5-11 cm long; rhachis densely stellate-hispid with branched, usually yellowish hairs; bracts persistent, 4 -7 x 2 -3 mm, stellate-hispid, somewhat leaf-like; verticillasters 4-6flowered, occasionally less, 5-10 mm apart.Calyx 5-6 mm long, stellate-hispid; upper lip ovate, acute, 2 mm long, decurrent; lower 4 teeth deltoid-subulate, up to 2 mm long.Corolla white, often tinged with mauve, 12-16 mm long; tube 10-12 mm long, tubular, 2.5 mm wide, often slightly constricted at the throat, sparingly pubescent (densely so on the lips); upper lip 1.5 mm long; lower lip shallowly concave, 2-4 mm long.Stamens shortly exserted by 1,5-3 mm, not or scarcely exceeding the lower lip of the corolla; upper pair attached below the middle of the tube, filaments puberulous near the base; lower pair attached at the throat, filaments united only near the base or to about half their length.Stigma shortly bifid.Closely related to H. teucriifolia (Hochst.)Briq.as will be seen from the tubular corolla which is slightly constricted at the m outh, and the very shortly exserted stamens.It differs from H. teucriifolia in a few minor respects, namely, the narrower, "ericoid" leaves (although occasional broader, ovate leaves may be present), the shorter internodes, the tendency for the tomentum to be yellower in colour and the usually pubescent corolla tube.The two meet in the Transvaal, but do not appear to overlap; H. subvelutina is restricted to the m ountains from near Lydenburg and Pilgrim's Rest to Kaapsche Hoop, while H. teucriifolia is distributed from the eastern Cape Province through N atal to the Barberton area, appearing again in the mountains of eastern Rhodesia.

Orthosiphon subvelutinus
There is some indication of introgression in the south-eastern Transvaal.Specimens from Kaapsche Hoop tend to have longer internodes and, occasionally, glabrous corolla tubes, while an occasional specimen from near Barberton may have pubescence on the corolla tube (apart from ihe lips which are always pubescent on the outer surface).Usually leaf shape and the colour of the pubescence can be used as a guide in such cases and it is felt that both species can justifiably be upheld.See also notes under H. albiflora (p.10).
N. E. Brown, I.e., considered that in some specimens the filaments of the anterior pair of stamens were free to the base.This was not confirmed in the present study though admitedly more flowers should be examined than is possible in a herbarium.The degree of union was variable, from about 0,5 mm to 1.5 mm, the latter representing about half the length of the filaments.
Locally frequent in mountain grassland at altitudes of 600 to 1 500 m at scattered localities from Stutterheim District in the eastern Cape, to N atal and the Barberton District of the Transvaal, appearing again in the mountains of eastern Rhodesia.Its relationship with H. subvelutina is discussed under that species.It also resembles the following species, H. albiflora, which can readily be separated by its lack of stellate (branched) hairs.
Apparently H. teucriifolia is not readily eaten by stock and tends to increase on veld which is subjected to overgrazing.Woody shrublet 30-150 cm tall; branches markedly woody towards the base, somewhat gnarled and branching, procumbent to ascending, villous, densely beset with leaves and short leafy shoots.Leaves sessile, ericoid; blade linear to linear-elliptic, 10-30 mm long, 1,5-5 mm broad, stiff, subglabrous and shiny to appressed villous and blackish above, densely appressed villous below with long white matted hairs; apex and base tapering; margin strongly revolute, entire.Inflorescence simple or with a pair of branches near the base, 5-10 cm long; rhachis glandularhispid; bracts deciduous, ovate, acute, 5-8 x 3-5 mm, sparingly pubescent; verticillasters mainly 6-flowered, 5-15 mm apart.Calyx 6-8 mm long, glandular-hispid; upper lip ovate, rounded, 2 mm long, decurrent; lower 4 teeth deltoid-subulate, up to 2 mm long.Corolla white, 12-15 mm long; tube 10-12 mm long, curved, glabrous, tubular, expanding to 3 mm wide about the middle and then parallel sided or slightly constricted at the mouth, upper lip very small, less than 1 mm long; lower lip concave, 2-3 mm long Stamens exserted by 4-6 mm, exceeding the lower lip of the corolla; upper pair attached below the middle of the tube, filaments finely puberulous in the lower half; upper pair attached at the throat, filaments united for almost their entire length.Stigma minutely bifid.
Found am ong quartzite rocks, often with semialpine flora at altitudes of 1 800 to 2 400 m, in the mountains o f the eastern Transvaal and extending to northern Swaziland.The main flowering season is from November to March.The hard, narrow ("ericoid") leaves superficially, resemble those of H. subvelutina and H. teucriifolia but are easily distinguished by the lack o f stellate (branched) hairs.H. albiflora is a woody, freely branched plant which grows among rocks where it is fairly well protected against fire, whereas the other two species form annually a number of slender stems from a thick woody rootstock in response to repeated grass fires.H. albiflora also has a slightly longer corolla and the stamens are exserted beyond the lower corolla lip, while the filaments of the lower pair of stamens are united nearly to the apex.
Distributed from central to eastern Transvaal* Swaziland and northern Natal, in dense grassland, often among rocks, mainly at altitudes of 1 000 to 1 800 m.The species is characterized by the narrowly tubular corolla, scarcely expanding towards the throat; the longish upper lip of the corolla which almost equals the lower lip; and the fact that the upper pair of stamens are never exserted.In certain other species the upper pair of stamens are very short but eventually they are slightly exserted, e.g.H . subvelutina, H. teucriifolia and H. persimilis.
Two subspecies are recognized which are separated mainly on the presence or absence of stellate (branched) hairs (see key to species, p. 2) and to some extent of leaf shape.Stellate (branched) hairs absent throughout the plant; leaves narrowly elliptic to oblanceolate or obovate.
Distribution and ecology as for the species, though absent from southern Swaziland; flowering is mainly from October to February.Stellate (branched) hairs present on stems, leaves and bracts; leaves ovate to ovate-rotund; florally in no way different from the typical.F i g .4. Found in south-western Swaziland, the Piet Retief District of Transvaal and the Hluhluwe area of N atal; recorded in flower from October to January.Normally, subsp.heterotricha does not differ in floral characters or growth habit from the typical and thus subspecific status is considered appropriate.It occurs slightly to the south-west of subsp.pretoriae and no overlapping in distribution has yet been found.

0/jrrr 7
The specimen Ward 3960 has an unusual habit consisting of a slender branched stem about 30 cm tall, apparently not arising from a woody rootstock as in the normal behaviour of the species.Florally it does not deviate from H. pretoriae and it possesses the stellate pubescence of subsp.heterotricha.The unusual habit may be the result of the absence of fire over a period of years or it may represent a distinct ecological form adapted to the lower altitude.
Found in m ountain grassland subjected to periodic burning, in the mountains behind Barberton, in Swaziland and in the Piet Retief district; flowering takes place in spring while the grass is still short, though it can continue until later depending on local conditions.In habit and ecology H. modesta resembles H. pretoriae (Guerke) Ashby and H. thorncroftii (N.E.Br.) Ashby in being small, spring-flowering shrublets, sending up annual shoots from a woody rootstock often before the first rains occur, and is most noticeable after the grass has been burnt.
From H. pretoriae it is readily distinguished on the floral characters: in H. pretoriae the verticillasters are 6-flowered, the corolla scarcely widens towards the mouth and the upper pair of stamens remains included in the corolla tube; in H. modesta the verticillasters are 2-flowered, while the corolla widens towards the mouth and all four stamens are well exserted.
The individual flowers of H. thorncroftii are similar to those of H. modesta but again the verticillasters are 6-flowered, the leaves are long and narrow (1 ,5 -3 ,5 cm long), and the bracts are longer (8-20 mm) and more colourful, persisting as a con spicuous apical coma.An occasional specimen of H. thorncroftii has leaves shorter and wider than usual and such specimens appear to be somewhat intermediate, but the 6-flowered verticillasters and conspicuous bracts place them without doubt in H. thorncroftii.
Another dwarf species of the eastern Transvaal highveld, S. foloisa S. Moore, has 2-flowered verti cillasters, but the leaves are much larger (2-6 x 1-3 cm), the inflorescence is usually paniculate and the bracts are large and conspicuous.
There is a certain amount of variation included in the specimens of H. modesta cited above, which calls for further investigation.Three specimens from near Havelock, Acocks 12867, Codd 1623 and Compton 29123, have shorter and broader leaves with more villous pubescence on stems and leaves than the typical form.However, Mauve 4807 from near Barberton is somewhat intermediate and so separate rank for the villous form does not seem to be justified.The specimen Leipoldt s.n.from Piet Retief is more robust than usual for the species.It was given the manuscript name H. nervosa by Ashby, who refrained from publishing it until further material became available.
A mountain grassland species known from only one gathering at 3 000 m in the N atal Drakensberg.The habit and corolla shape suggest a relationship to H. transvaalensis (Schltr.)Ashby, but the leaves of the latter are acute and markedly toothed while the apex of the inflorescence is adorned by a coma of colourful bracts.
N. E. Brown, I.e., quotes this species as affording an example of the lower pair of filaments being free or united on the same plant.There are two capsules mounted on the type specimen, one marked " A, flower with filaments free" and the other " B, flower with lower pair of stamens united nearly to the apex" .It must be concluded that Flower A must have been abnormal or badly squashed in pressing.There are several good flowers on the sheet and in at least six of them the lower pair of filaments are obviously united to near the apex without the need for dissecting them.More material of the species is desired for further study.
Shrub, much branched, 1-1,2 m tall; branchlets shortly tomentose.Leaves shortly petiolate; petiole 1-3 mm long, tomentose; blade obovate to oblanceolate, 15-25 mm long, 6-11 mm broad, sparingly hispid above, hispid and gland-dotted below, apex rounded, base obtuse to cuneate, margin obscurely crenate-dentate mainly above the middle.Inflorescence usually sparingly branched towards the base, 10-15 cm long; rhachis sparingly strigilose; bracts ovate to broadly elliptical, 14-16 mm long, 6-8 mm broad, mauve-pink subglabrous to sparingly pubescent; verticillasters 2-flowered; pedicels 2-3 mm long.Calyx when flowering 8 mm long, sparingly glandularhispidulous; tube 6 mm long; posticous lobe broadly ovate, rounded, 2 mm long, margin decurrent; lateral teeth deltoid-subulate, 1 mm long; anticous teeth subulate, 2 mm long.Corolla mauve, 25-28 mm long, puberulous; tube 20-22 mm long, widening gradually towards the apex, m outh 4-5 mm wide; posticous lip 2 mm long; anticous lip concave, horizontal or recurved, 5 mm long.Stamens exserted by 9-11 m m ; posticous stamens attached about the middle of the corolla tube, filaments free, pubescent towards the base; anticous stamens inserted in the throat of the corolla, filaments united to the apex.Style exserted by 15 mm, apex shortly bilobed.In the herbarium , H. ramosa is reminiscent of H. transvaalensis (Schltr.)Ashby but the two are not likely to be confused in the field because of differences in habit and ecology.H. ramosa is a much-branched bushy shrub growing on rocky, wooded hillsides and cliffs, while H. transvaalensis is adapted to grassland which is periodically burnt, with the result that it develops a woody rootstock from which several branches arise annually.There are also differences in shape, pubescence and nervation of leaves, with H. ramosa having leaves more obovate and less dentate than those o f H. transvaalensis.An im portant difference, in addition, are the flowers produced singly in the axils of the bracts in H. ramosa while, in H. transvaalensis each bract subtends usually three flowers.
In the field H. ramosa would probably remind one o f Syncolostemon latidens (N.E.Br.) Codd, thus emphasizing the close affinity of the two genera.However, the calyx of H. ramosa is clearly of the Hemizygia type, having a broad upper lobe, decurrent on the tube, with the remaining four teeth ending in subulate, almost spine-like points.

Orthosiphon transvaalensis
Locally common at medium altitudes of 1 000 to 1 700 m in the eastern Transvaal m ountains from the M ariepskop and Lydenburg areas southwards to Barberton, on grassy slopes and flats, usually among rocks.
H. transvaalensis is related to the next two species, H. foliosa S. M oore and H. thorncroftii (N.E.Br.) Ashby, but is a more robust species, up to 1 m tall, with usually broader bracts and longer flowers (corolla tube 14-17 mm long).Depauperate specimens may be only 20 cm tall with narrow bracts and these may be confused with H. thorncroftii which, however, usually has narrowly elliptical leaves while the corolla tube is 8-10 mm long.H. foliosa tends to be decumbent, usually with large, elliptical leaves rounded at the apex, the corolla is smaller (tube about 10-12 mm long), and the verticillasters are 2-flowered.
Occasional specimens of H. transvaalensis branch freely and produce numerous small leaves, giving specimens a broom-like appearance.Such a specimen was described as Orthosiphon wilmsii Guerke.However, there are many intermediates linking it with typical H. transvaalensis in which branching is sparing and leaves fewer and larger.There is also a good deal of variation in leaf shape, toothing of the margin and pubescence.It grows under warm er and drier " middleveld" conditions than the majority of eastern Transvaal species and the showy bracts and flowers have led to it being cultivated with some success in Pretoria.
Found in dense m ountain grassland, often am ong rocks, at altitudes of 1 300 to 1 700 m in the south eastern Transvaal and western Swaziland.May be distinguished from H. transvaalensis and H. thorncroftii by the 2-flowered verticillasters and the large, ovate to ovate-elliptic, entire or distantly toothed leaves.In some specimens the leaves are only 2 cm long, but these are probably immature.There is also a good deal of variation in pubescence, from puberulous to pillose leaves.The terminal bracts also vary in size, in some specimens being less than 1 cm long, but are always purplish in colour.The type of H. humilis is such a specimen and the leaves are somewhat smaller than usual but the modern range of material links it with H. foliosa.
Individual flowers resemble those of H. modesta but the latter species has 2-flowered verticillasters and lacks the colourful apical bracts of H. thorncroftii.
Known only from the Nelspruit-Barberton area of the eastern Transvaal where it grows in grassy places among rocks in lowveld woodland at altitudes o f about 1 000 m. H. persimilis shows a com bination of unusual features in the genus, some of which are also found in H. pretoriae, a species of similar stature and ecology.For example, the narrow corolla tube expands abruptly at the mouth forming what appears to be a longish upper lip nearly equal in length to the lower lip, and the stamens are very shortly exserted (the upper pair is included in H. pretoriae and exserted by 1-2 mm in H. persimilis).In addition, H. persimilis differs in the upper pair of stamens being attached very near the base of the corolla (about one third up the tube in H. pretoriae); the lower pair of filaments may be free or united for only about 0 ,5 mm at the base (united for most of their length in H. pretoriae)', the stigma is clavate (slender and shortly bifid in H. pretoriae)-, and the bracts are large and showy (small and inconspicuous in H. pretoriae).
There are thus as many differences as there are simila rities between the two species, both of which are rather aberrant members of the genus.
The fact that the filaments of the lower pair of stamens are united only at the base may be put forward as an example which breaks down the distinction between Hemizygia and Orthosiphon.However, the structure is different.In Orthosiphon the filaments (free to the point of attachm ent) continue down as distinct and separate ridges on the corolla tube; in H. persimilis the filaments are united at their point of attachm ent and continue as a single confluent ridge down the corolla-tube.
Restricted to north-eastern Transvaal from the Soutpansberg to near Duiwelskloof on rocky, wooded hillsides and at forest margins, at altitudes of 1 000 to 1 600 m.A strongly arom atic plant allied to the next species, H. canescens (Guerke) Ashby, but has more ovate leaves, longer petioles and longer corolla tube.

25.
Hemizygia canescens (Guerke) Ashby in J. Bot. Lond. 73: 354 (1935);Com pton, FI. Swaz. 67 (1966);Ross, FI. N atal 306 (1972).Lectotype: Transvaal, W onderboom poort, Rehmann 4507 (Z, lecto.;K).Herb, probably perennial, woody and branched below, 30-60 cm tall; stems often branched, shortly greyish-tomentose, often crisped or, occasionally, sparse but not villous.Leaves subsessile or shortly petiolate; petiole up to 5 mm long; blade linear or linear-lanceolate to lanceolate or, rarely ovatelanceolate, 2 ,5 -5 ,5 cm long, 3-15 mm broad, concolorous, densely canescent on both surfaces to sparingly short crisped tomentulose and somewhat rugose, nerves prom inent below; apex acute, base cuneate to attenuate; margin finely to fairly coarsely serrate-dentate in the upper half to two thirds.Inflorescence simple to freely branched, 7-25 cm long, lax; rhachis crisped-tomentulose to finely glandularhispidulous; bracts early deciduous, small, ovate, ca. 2 x 1 mm; verticillasters 4-6-flowered, 1-3 cm apart.Calyx 5 mm long at anthesis, enlarging in fruit, glandular-tomentulose to hispidulous; upper lip ovate to subrotund, 2 mm long, decurrent; lower 4 teeth deltoid-subulate, becoming bristle-like, up to 2 mm long.Corolla white or pale mauve or purplish, 14-17 mm long, finely pubescent; tube 10-13 mm long, widening abruptly about 2 ,5 mm from the throat to 3-4 mm wide at the th ro at; upper lip a small appen dage; lower lip concave, 3-4 mm long.Stamens exserted by 10 mm, well exceeding the lower lip; upper pair attached about 4 mm from the base of the tube, filaments puberulous below; lower pair attached at the throat, filaments united for most of their length.A good deal of variation in leaf shape is included in H. canescerts from linear (3-4 mm wide), in the dry western extremity of its range in the Mafeking District, to lanceolate and ovate-lanceolate (up to 15 mm wide) in more mesophytic areas.The species is diagnosed on the basis of the short canescent, often crisped tom entum of stems and leaves though, towards the north of the range, in the Waterberg, Potgietersrus and Tzaneen Districts, the pubescence is more scanty and somewhat rougher.This form was separated as Orthosiphon affinis N.E.Br., but Ashby reduced it to synonymy under H. canescens.Although the extremes can be separated with close scrutiny under magnification, there are numerous intermediates linking them.Supperficially H. canescens closely resembles H. petrensis but the latter may be recognized by the presence of long villous hairs on the stems, although the pubescence of the leaves is often similar.The latter is a more western species, entering the northern and eastern Transvaal lowveld, and is also very variable (see p. 19).H. canescens appears to be a fairly clearcut entity with a distribution distinct from H. petrensis and thus it seems justified to uphold both as species.However, two specimens from the Waterberg in S.W. Africa, Boss sub TRV 35003 and De Winter 2799, have pubescence resembling H. canescens and this areas should be investigated further.

Orthosiphon linearis
Found in open places in dry woodland in South West Africa and northern Cape Province; also in Rhodesia and Angola.Diagnostic features are the linear, subglabrous leaves and the subglabrous to sparingly villous stems which have a somewhat varnished appearance.H. petrensis is closely related to it and, as may be expected, some specimens are difficult to allocate with certainty, but H. petrensis usually has a strong development o f villous hairs on the stems and, to a lesser extent, on the leaves (see also below).Some specimens of H. canescens have linear leaves but the dense, short pubescence on stems and leaves can be used to exclude such specimens from H. linearis.

H em izygia mossiana (G ood) Ashby, I.e. 356 (1935).
Strongly arom atic herb, annual or perennial, 20-60 cm tall, branching near the base and woody below, with a woody taproot; stems villous to densely villous with long, spreading greyish-white hairs, quadrangular and often strongly ribbed along the angles.Leaves subsessile or shortly petiolate; blade variable from linear-lanceolate to oblong-lanceolate or ovate-lanceolate 2-5 cm long, 5-15 mm broad, sparingly to densely pilose or canescent, often with long and short hairs intermingled; apex acute, base cuneate to attenuate; margin obscurely to distinctly and somewhat distantly toothed.Inflorescence 8-20 cm long, lax, simple or with a pair of branches near the base; rhachis glandular-villous; bracts caducous, small, ovate to broadly ovate, 3 m m x 2 mm, pubescent; verticillasters 4-6-flowered, 1-3 cm apart.Calyx 4-5 mm long at anthesis, enlarging in fruit, glandular-hispid to villous; upper lip broadly ovate or subrotund, purple, 2 mm long, decurrent; lower 4 teeth deltoid-subulate, 1,5 mm long.Corolla pinkish to lilac or voilet, finely pubescent, 13-15 mm long; tube 9-12 mm long, widening abruptly about 3 mm from the apex to 2,5-3 mm wide at the throat; upper lip a small appendage; lower lip concave, 3-4 mm long.Stamens exserted by 8 mm, exceeding the lower lip; upper pair attached 2-3 mm from the base of the tube, filaments puberulous below; lower pair attached at the throat, filaments united for more than two thirds their length.Stigma somewhat clavate.The three species H. canescens, H. linearis and H. petrensis form a closely related group with alm ost identical floral characters and small, inconspicuous bracts.H. canescens may be dinstinguished on the basis of the dense, short and often crisped pubescence on stems and leaves and is distributed mainly on the high plateau formed by the northern Cape, south western and central Transvaal, extending to eastern Transvaal, Swaziland and Natal.In H. linearis, which is the oldest name, the leaves are linear to filiform (occasionally some leaves up to 5 mm broad) and leaves and stems are subglabrous or with scattered long hairs.Its distribution is more tropical, from Rhodesia to northern South West Africa and northern Cape.It overlaps with H. petrensis but the com bination of narrow leaves (less than 5 mm wide) and subglabrous, somewhat varnished stems, serves to identify H. linearis.

Recorded from northern
H. petrensis, with villous stems and with leaves rarely narrower than 5 mm, varies a good deal in leaf shape from narrowly lanceolate to ovate-lanceolate, while the pubescence of the leaves may be villous to shortly canescent, or a mixture of the two.Occasional inter mediates are found, for example the two specimens from the W aterberg Plateau in S.W. Africa might be better placed in H. canescens, and further investi gation in this area is desirable.Occasionally the stems and leaves are sparingly villous, approaching the condition of H. linearis.Orthosiphon mossianus was based on such a plant.Ashby, I.e., distinguished it from H. petrensis on the presence o f petioles, but this varies as much as the degree o f pubescence and leaf shape, so that O. mossianus and O. varians (ovate-lanceolate leaves) are best regarded as forms of H. petrensis.O. holubii is in no way distinct from typical H. petrensis.
The types of O. dinteri and O. engleri have not been seen.Launert & Schreiber, I.e., include them in H. petrensis and, judging from the descriptions, this appears to be the correct decision.
On this basis, H. petrensis is distributed from Angola and Rhodesia southwards to W indhoek in S.W. Africa and to the northern and eastern Transvaal lowveld, reaching as far south as K om atipoort.Superficially it resembles H. bracteosa which has a somewhat similar distribution in our area, but the latter species has a conspicuous com a o f white to rose-purple bracts, the flowers are usually whitish, not mauve to violet as in H. petrensis, and the corolla is usually shorter.Herb, probably annual, 25-75 cm tall, sometimes woody and branching below, forming a soft aromatic bush; stems sparingly to densely pilose with long weak multicellular hairs.Leaves sessile; blade narrowly lanceolate to oblong-lanceolate 4-9 cm long, 8-24 mm broad, hispidulous and darker above, sparingly to densely canescent below; apex acute, base attenuate; margin somewhat distantly serrate-dentate.Inflores cence paniculate or simple, lax, 12-30 cm long; rhachis glandular-hispidulous; bracts large forming a persistent apical coma, white to rose-purple, 5 -1 0 x 4 -8 mm; verticillasters 4-6-flowered, 1-2,5 cm apart.Calyx 5 mm long at anthesis, glandular-villous, enlarging in fruit; upper lip broadly ovate to sub rotund, purple, 2 mm long, decurrent; lower 4 teeth deltoid subulate, up to 2 mm long, becoming bristle like.Corolla white or tinged with mauve (rarely violet), 10-11 mm long, puberulous on the lips otherwise glabrous; tube 7-8 mm long widening gradually to 2 ,5 -3 mm at the throat; upper lip a minute appendage; lower lip concave, 3 mm long, often deflexed.Stamens exserted by 5-6 mm, the lower pair longer than the upper pair, exceeding the lower lip of the corolla; upper pair attached below the middle o f the tube, filaments finely puberulous for half or more o f their length; lower pair attached at the throat, filaments united to near the apex.Stigma somewhat clavate, entire.
W idespread from Senegal and Tanzania southwards to northern South West Africa, northern Botswana, M ozambique and the eastern Transvaal Lowveld.Found am ong rocks, in watercourses and in open sandy places in relatively dry tropical woodland.
In habit, ecology and distribution within our area, H. bracteosa resembles the former species, H. petrensis, but may be distinguished by the conspicuous coma of large, whitish to rose-purple bracts, the usually whitish corolla which is usually shorter than the mauve to violet corolla of H. petrensis.The leaves are canescent as in H. canescens but the stems are weakly pilose, while the conspicuous bracts distinguish it from the latter species.H. bracteosa is remarkably uniform considering its wide distribution from Senegal and Tanzania to Southern Africa.
F i g .7. Found in shallow soil among rocks in open wood land at the southern end of the Lebombo Range near Mkuze.N a t a l .-2732(U bom bo): Lebom bo M ts., near M kuze (-C A ), M o ll 3158; Mkuze Poort (-C A ), W ard 4074.

*
Ashby points out that, in the Transvaal Museum, N o.3125 is H. thorncroftii while N o.3123 is H . transvaalensis.
Stigma somewhat clavate.Distributed in a broad band from the Mafeking District of the Cape Province, across south-western and central Transvaal to eastern Transvaal, avoiding the high mountains, extending to Swaziland and northern Zululand; am ong rocks in open arid to moist woodland and m arginal grassland at altitudes of 300 to 1 700 m.
South West Africa and northern and eastern Transvaal, among rocks, in open places and watercourses in semi-arid woodland at altitudes of 200-700 m in the Transvaal and up to 2 000 m in the Windhoek area of South West Africa.Also in Angola and Rhodesia.