Studies in the genus Lotononis ( Crotalarieae , Fabaceae ) . 5 . A new species of the L . involucrata group ( section Polylobium ) from the north-western Cape Province

A new species of the section Polylobium (Eckl. & Zeyh.) Benth. of Lotononis (DC.) Eckl. & Zevh. is described, namely L racemiflora B-E. van Wyk. The species, known only from a single collection near Clanwilliam in the north­ western Cape, is closely related to L involucrata (Berg. ) Benth. and L angustifolia (E. Mey.) Steud.


INTRODUCTION
Lotononis involucrata (Berg.)Benth.and related species differ from other species of the section Polylo bium (Eckl.& Zeyh.)Benth. in the subterranean caudex from which flowering shoots develop annually.Stipules are paired or absent and never single or markedly dimor phic as in other species.The umbellate inflorescence in all the species which Diimmer (1913) included in Polylo bium was used as a diagnostic character for the section.
The new species described below is morphologically intermediate between L. involucrata (Berg.)Benth.and L. angustifolia (E.Mey.) Steud.and is obviously very closely related to these species.However, the inflores cence is a true raceme.Inflorescence structure is there fore no longer a useful diagnostic character for distin guishing the section Polylobium.It may indeed be argued that Polylobium sensu lato is an artificial group which has resulted from the excessive weighting of inflo rescence structure as a diagnostic character.
L. racemiflora is closely related to L. angustifolia but differs in the many-flowered racemose inflorescence (few-flowered and umbellate or subumbellate in L. an gustifolia), the semicordate stipule base and the more densely pilose vestiture.It is also similar to L. involu crata.. but differs from this species in the racemose inflo rescence.the size and texture of the leaflets (larger and more coriaceous than in L. involucrata), the size and shape of the stipules and the much larger standard and wing petals.The new species may be confused with L. angustifolia and L. involucrata when not in flower, but the inflor escence structure is quite different.It is known from a single collection near Clanwilliam in the north-western Cape, where it was found on an old land in Fynbos-Strandveld vegetation.Figure 2.

FIGURE
FIGURE l .-Lotononisracemiflora.A, habit, showing a flowering branch, the persistant root and the long, racemose inflor escence.B l , B2, B3, leaves and stipules, showing the variation in size and shape and the pilose vestiture: B l , abaxial view of a mature leaf taken from a basal node, B2, adaxial view (note the vestiture), B3, abaxial view.C, calyx opened out, with the up per lobes to the left, vestiture not shown; D, standard petal; E, wing petal; F, keel petal, show ing the small size and pointed apex; G, pistil; H, immature fruit in lateral view, showing the verrucose upper suture; l l , I2, I3, long anther, carinal anther and short anther respectively; J, bract.All from Acocks 15171.Scales in mm.
FIGURE 2.-The known geographical distribution of Lotononis race miflora.