Nord. J. Bot. - Section of tropical taxonomy

A new species of Tephrosia (Leguminosae) from southern Yemen, with a note on the identity of T. geminiflora

Mats Thulin

Thulin, M. 1994. A new species of Tephrosia (Leguminosae) from southern Yemen, with a note on the identity of T geniin$floru. - Nord. J. Bot. 14: 487-489. Copenhagen. ISSN 0 107-055X.

Teyhrosiu hadrumuuticu. a new species from the coastal plain of Hadramaut in southern Yemen, is described and illustrated. T gemin;floru, previously regarded as an endemic of Hadramaut. is reduced to a synonym of 7: suhtr~loru.

M. Thulin, Dept Uppalu, Swetlm.

Sv.stenlr:tir Botuny, Uypsdu University, Villuviigm 6, S- 7.52 36

Introduction The pantropical genus Tephrosia Pers. is in southern Yemen represented mainly by the more or less wide- spread species 7: apollinea (Del.) Link, 7: heterophylla Vatke, 7: nubicu (Boiss.) Bak., 7: piirpurea (L.) Pers., 7: suhtriflora Hochst. ex Bak. and 7: uniflora Pers., which were all seen during field work in the area in Sep-Oct 1992. 7: dura Bak., a spectacular species with bright red flowers only known from southern Yemen and northern Somalia (Thulin 1993) was also seen in Hadramaut (Thu- lin et al. 8239), along with a distinctive new species described below.

Tephrosia hadramautica Thulin sp. nov. Type: Thulin, Eriksson, Gifri & LIngstrom 802 I , Yemen, Ha- dramaut, 26-27 km on the pipeline route starting 15 km NE of Riyan, 14"52", 49"30E, 3 Oct 1992 (UPS holotype, Aden Univ., E, K isotypes).

Species nova a 'I: scopulata Thulin foliis subsessilibus, floribus majoribus et leguminibus glabris differt. - Fig. 1.

Broom-like shrublet, up to c. 0.5 m tall; young stems green, finely ribbed, glabrous to sparsely puberulous with minute appressed white hairs. Leaves 1 -foliolate, sparse,

and plants often * leafless; leaflet linear, 12-43 x I .5-2.5 (-3.5) mm, sparsely puberulous with minute appressed hairs on both sides; margins somewhat thickened; mid- vein prominent beneath; petiole c. 1 mm long, appressed puberulous. Stipules subulate, up to 2 mm long but often rudimentary. Flowers in upper leaf-axils and also in lax pseudoracemes up to 15(-25) cm long and with up to 7 nodes, each with 1-4 tlowers; bracts subulate, up to c. 2 mm long, persistent; pedicels 3.5-8 mm long, somewhat elongating in fruit, appressed puberulous. Calyx c. 3-3.5 mm long, appressed puberulous, divided about halfway into narrowly triangular lobes, the lowest slightly longer than the others and the two upper united at the base. Corolla pale yellow with reddish markings; standard sub- circular, c. 8 mm long including claw, appressed white pubescent outside, blade broadly cuneate at the base; wings & elliptic-oblong, exceeding the keel, blade auricu- late at the base; keel c. 8 mm long, glabrous. Stamens with the upper filament lightly attached, widened and slightly callous just above the base; filament-sheath c. 7 mm long, free parts c. 0.6 mm long; anthers c. 0.4 mm long. Ovary linear, puberulous along margins; style sharply upcurved, glabrous, c. 2 mm long, not twisted, tapering towards the penicillate capitate stigma. Pods slightly upcurved towards apex, linear-oblanceolate, with a deflexed beak, 23-30 x c. 4 mm, glabrous or with a few minute hairs along margin and near apex; distance be-

Accepted 10-3- 1994 0 NORDIC JOURNAL OF BOTANY NORD. J . BOT. 14: 4874x9

Nord. J . Bot. 14 ( 5 ) (1Y94) 487

Fig. I . Tephrosiu hadramautica. - A : Habit, 0.7. - B: Flower, x 4. - C: Standard, x 4. - D: Tip of ovary, x 4. - E: Fruit, x 0.7. - F: Seed, x 4. - A. D from Thulin et al. 8027; B. C. E, F from Thulin et al. 8021.

tween centres of adjacent seeds greater than width of pod. Seeds 2-5, longitudinal. broadly elliptic, flattened, c. 2.4 x 1.8 mm; hilum subcentral, exarillate. - Fig. 1.

Distribution and habitat. 7: hadramautica is known only from the area along Wadi Arf near Riyan in the Hadra- maut Region of Yemen. Several populations were seen in October 1992 on the semi-desert plain between the es- carprncnt of the Jol Plateau and, the coast at altitudes between 140 and 220 m. Here the species grows in stony ground along Wadi Arf and its tributaries.

The vegetation along the wadis in the area consists of

an open Acacia-Commiphora bushland including also shrubs and small trees of, e.g., Salvadora persica, Ta- verniera glauca, Gossypium incanutn, Delonix elata. Caesalpinia erianthera, Turraea parvifolia, Sterculia africana, Jatropha spinosa, Maerua thnmsonii and Bala- nites aegyptiaca. T. hadramautica often grows associated with other broom-like shrublets and particularly Kickxia spiniflora (Scrophulariaceae), another endemic of the ar- ea, has a striking similarity in habit.

Taxonomic remarks. T, hadramautica is without doubt closely related to T. scopulata Thulin (1989) in north- eastern Somalia. T. scopulata was previously regarded as an isolated species in subgen. Tephrosiu, but obviously it forms, with 7: hadramautica, a pair of vicarious sister species on either side of the Gulf of Aden. The two species agree in their broom-like habit, sparse indumen- tum of minute appressed hairs, I-foliolate leaves, short subulate stipules, long lax pseudoracemes, yellowish co- rolla, non-twisted tapering style, and longitudinal distant seeds. Still, 7: hadramautica is quite distinctive and dif- fers from T. scopulata in its practically sessile, always I-foliolate leaves (petiole 10-100 mm long and leaves occasionally 2-3-foliolate in T scopulatu), its larger flowers with keel c. 8 mm long (c. 4 mm in T. scopulara), and glabrous (not appressed puberulous) pods).

Collection other than type. Yemen. Hadramaut: 20 km on the pipeline route starting 15 km NE of Riyan, 14"49'N, 49"31'E, 3 Oct 1992, Thulin et al. 8027 (UPS).

The identity of T. geminiflora Tephrosia geminiflora Bak. was based on the collection Hirsch 94 from Hadramaut. The locality is not further specified, but as Hirsch started his journey in Mukalla it could be from the same general area as 7: hadramautica. The name T. geminijlora has not been used for any other material than the type and the identity of the plant has not been discussed since its publication.

Already from the description i t is clear that T. gemi- niflora cannot be identical with 'I: hadramautica. I t is said to be a herbaceous perennial with 3-foliolate white- sericeous leaves, axillary flowers, short pedicels, short wings, and many-ovulate ovary. It is by its author said to be near T, subtriflora. A fragment of the type is preserved at K and in my opinion it represents a form of T. sub- trifloru with narrow leaflets. The variable T, subtrtjlora occurs in Hadramaut and we saw it , e.g., at 15"50", 49'12'E on the Jot Plateau (Thulin et al. 8319). This is not far from the route of Hirsch and also represents a form with narrow leaflets similar to the type of 7: geminijlora.

The following synonymy is proposed:

488 Nord. 1. Bot. 14 ( 5 ) (1994)

T. subtriflora Hochst. ex Bak. Baker 1871: 117.

T. geminijlloru Baker 1895: 316, syn. nov. -Type: Hirsch 94, Yemen, Hadramaut, without precise locality, I893 (B holotype, ?destroyed, K fragment).

Acknowledgements - The field work in Yemen was supported by a grant from “Regnells botaniska resestipendium”. I am indebted to Ms Kerstin Thunberg for the drawing in Fig. 1.

References Baker, J. G. 187 I . Papilionaceae. - In: D. Oliver (ed.), Flora of

Tropical Africa 2: 1-258. L. Reeve & Co., London. - 1895. Trphrosiu geminijlora. - Kew Bull. 1895: 316.

Thulin, M. 1989. New and noteworthy species of Leguminosae in NE tropical Africa. - Nord. J. Bot. 8: 457-488.

- 1993. Fabaceae. - In: M. Thulin (ed.), Flora of Somalia I : 341--465. Royal Botanic Gardens, Kew.

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