Two new species of Erica (Ericaceae) from the Langeberg, Western Cape, South Africa

Two new species o f the genus Erica L. from the north-facing slopes o f the Langeberg are described— E turneri. known only from the type locality on Zuurbraak Mountain and E. euryphylla. occurring on the same mountain slope, as well as on the middle north-facing slopes o f Hermitage Peak near Misty Point in the Marloth Nature Reserve above Swellendam.


INTRODUCTION
The two species described in this paper are placed in section %Ceramia in which there are many species asso ciated with damp, shaded or wet habitats.Most are soft, low shrublets, either erect and compact or diffuse and sprawling, with long, delicate main branches and often with open-backed leaves (Oliver & Oliver 2002).Both new species possess recaulescent bracts and bracteoles and have broad, flat leaves with distinctly thinned mid ribs towards the apices, allying them morphologically with E. oxycoccifolia and E. cordata respectively, rather than with the E. planifolia group, in which the bract is not recaulescent and is leaf-like and the leaves have apically thickened midribs.E rica tu rn e ri E.G.H.Oliv., sp.nov., foliis 3-natis, ramis foliis bractea bracteolisque pilis glandulosis simplicibusque, bractea recaulescenti, corolla ± 3 -4 x 2 .5 -3.5 mm pilis brevibus simplicibus, ovario pilis sparsis.Figura 1.
Flowering tim e: May to August.Figure 1.Pollination syndrome: the pollination syndrome of Erica tum eri is unresolved.The presence o f anther appendages and well-developed nectaries suggest entomophily, although no potential pollinators, flying or crawl ing, have been observed during visits to the ten known stands.It seems improbable, however, that a flying insect wrould be able to penetrate the tangled, glandular leaves and stems o f the species, to reach flowers that are often pressed against rock faces, or entirely contained by the plants aforementioned habit.Preliminary studies into the pollination syndromes o f E. limosa L.Bolus and E. salteri L. Bolus, suggest that large ants may play an important role in the pollination o f moisture-loving Erica species with a low, diffuse, entwined habit, as well as with small (1-5 mm long), cup-shaped flowers (Turner pers.obs.).

Diagnostic features and discussion
Distribution and habitat: Erica tum eri appears to be confined to the catchment area o f the Klein-Sandrivier on the middle north-facing slopes of Zuurbraak Mountain in the Langeberg Range, ± 11 km southwest o f Barrydale (Figure 2) (Turner pers.obs.).The species has been seen at altitudes ranging from 580-950 m, on a substratum of quartzitic  ledges.This type o f microhabitat often provides only a small amount o f derived quartzitic sand and darker, peatty, organically derived accumulate in which plants may grow.It is unusual, although not unique, for an Erica species with a delicate growth form and markedly open-backed leaves such as E. turneri, to inhabit hotter, drier, north-facing mountain slopes, as well as to enjoy a generally north-facing aspect.However, the species grows in seasonally wet or damp, mostly shady crevices and recesses at the bases o f rocks and rock ledges, result ing in the majority o f specimens receiving potentially direct sunlight only in autumn and midwinter, the period over which the species flowers.Morphologically allied taxa such as E. oxycoccifolia, E. physophylla Benth.and E. utriculosa L.Bolus, which are by contrast confined to damp, shady, montane, south-facing habitats on gener ally wetter, south-facing slopes, would receive their most direct sunlight as well as optimum moisture availability in spring to early midsummer, the seasons in which their flowering occurs.Although the south and upper northfacing slopes o f Zuurbraak Mountain receive much precipitation and resulting seepage, the middle and lower north-facing slopes are comparatively dry.
Stands o f E. turneri growing in the non-perennial, eastern tributaries o f the Klein-Sandrivier do not receive direct runoff or seepage from the wetter, upper slopes, and plants in these more exposed habitats display red dish green leaves and produce flowers with a pink tinge at an earlier stage than well-shaded specimens.Stands growing in the Klein-Sandrivier Kloof enjoy a cooler, moister microclimate and the only south-facing speci mens o f the entire population are found in this kloof, in a steep, damp side gully.Here plants form low, matted hedgerows' at the base o f rock faces, individual plants attaining dimensions o f up to 450 x 400 mm.Given the populations' general aspect and habitat however (Turner pers.obs.), it is apparent that the species is capable o f surviving some relatively dry periods.It is therefore surprising, given its postulated relationship with other species o f §Ceramia.that in this situation, the species has almost totally open-backed leaves.In its specialized microhabitat, E. turneri grows in association with other delicate, lax, shade-loving species such as Troglophyton cupillaceum (Asteraceae), Centella macrodis (Apiaceae) and Gleichenia polypodioides(Gleicheniaceae).as well as other moisture-loving species such as Lobelia neglecta (Lobeliaceae), Drosera capensis (Droseraceae), Todea Barbara (Osmundaceae), E. caffra L., E. cubic a L., E. hispidula L., E. tenuis Salisb.(Ericaceae), Berzelia lanuginosa and Raspalia virgata (Bruniaceae) and sev eral low Restionaceae species.The following species described in this paper.E. euryphylla, although growing °n the same mountain slope, does not occur in direct association with E. turneri.Furthermore, the north-and south-facing slopes o f Zuurbraak Mountain together sup port at least 34 Erica species (Turner pers.obs.), nine o f these endemic to the Langeberg.
Flowering tim e: May to September.Figure 3.
Diagnostic features and discussion: within §Ceramia, Erica euryphylla shares several characters in common with species o f the E. cordata complex, in particular E. cordata Andrews, E. macrophylla Klotzsch ex Benth.and E. ocellata Guthrie & Bolus.These species also possess 3-nate, broad, open-backed leaves with densely woolly abaxial surfaces, adaxial surfaces with long, simple and gland-tipped hairs and a thickened midrib in the basal and median portions but in all instances not protruding beyond the lamina at the apex o f the leaf, stems with long, and gland-tipped hairs, sepals with red, stalked glands on the margins, glabrous adaxial surfaces, abaxial sur faces with long, simple and gland-tipped hairs, as well as woolly hairs in the sulcus, globose, 4-locular ovaries with lanate hairs, and manifest, muticous anthers.Variation in the anther morphology o f E. euryphylla has been noted however, with the occasional flower displaying two minute, aculeate, spreading appendages on the margins o f the filament just below the attachment to the thecae.These vestiges o f appendages are only clearly visible at a magnification of 25x or more.Such variation pertaining to the presence or absence of anther appendages within a spe cies is not unique, examples being E. anguliger (N.E.Br.)E.G.H.Oliv. in which appendages may be present or absent within a single flower (Oliver 2000) and E. aigentea Klotzsch ex Benth.(Turner in prep.).Significant char acter differences separating E. euryphylla from the E. cordata complex include a sparsely hairy, cup-to shortly urn-shaped corolla; variation in the type and placement of the bract on the pedicel (either partially recaulescent, basal to median and reduced, or partially recaulescent, basal and leaf-like) and leaves with only very slightly thickened and rolled-under margins as well as less dense, woolly hairs on the abaxial surface.The habit is generally far more lax than those of the compared species, with the excep tion o f E. ocellata, which may have a sprawling habit when mature (Turner pers.obs.).Character similarities and differences between E. euryphylla and E. turneri are discussed under the latter species in this paper.
Pollination syndrome: the pollination syndrome o f E. euryphylla is unknown.Although the species has mostly muticous anthers, only occasionally displaying minute anther appendages, it does possess well-developed nec taries and a capitellate stigma, suggesting some form of entomophily.A lack o f obvious wind-borne pollen dis charge when the plants are disturbed, as occurs in windpollinated species such as E. hispidula L. and E. muscosa (Sol.)E.G.H.Oliv., and the colour o f the species' flowers, suggest that it is not wind pollinated.
Table Mountain Sandstone (Turner pers.obs.).Plants occur in seasonally damp or wet, mostly shady crevices and recesses at the bases o f rocks and rock FIGURE 2. Known distribution o f Erica tum eri.
Distribution and habitat: E. euryphylla appears to be endemic in the middle and upper north-facing slopes of the Langeberg Range, on Zuurbraak Mountain and in the Marloth Nature Reserve (Figure4).It was recorded at the latter locality by Elsie Esterhuysen in 1983 on the Swellendam Trail between Boskloof and Goedgeloof huts and by Dave McDonald in 1989 from the western end of the Langkuilen Valley near Misty Point.Both Esterhuysen's and McDonald's specimens were found growing on similar north-facing slopes, in near-identical habitats to specimens from Zuurbraak Mountain-'in shelter o f overhanging rock' and 'in deep shade o f rocks' respectively, approximately 15 km west o f Zuurbraak Mountain.McDonald cited a latitude and longitude with his collection and a projection o f this point would appear to place Esterhuysens' collection no more than 2 km distant.E. euryphylla has been recorded at altitudes between 1 060-1 340 m. always on a substrate o f quartzitic Table Mountain Sandstone (Turner pers.obs.).Plants grow in pockets of quartzitic sand and darker, peatty.organically derived accumulate, in seasonally damp or wet, mostly shady crevices and recesses at the bases o f rocks and rock ledges.McDonald's specimen indeed cites a substrate of Might grey soil with humus'.Associated species are similar to those o f E. tum eri above but with E. ardens Andrews, E. triceps Link and several low Restionaceae species.The first stand o f the Zuurbraak subpopulation o f E. euryphylla was found by ecologist and walking partner Nick Helme.only minutes after E. tum eri was discov ered by the author o f this species.