Tephrosia uzondoensis F.M.Crawford

Crawford FM, Darbyshire I, Vollesen K. 2016. Tephrosia uzondoensis (Leguminosae: Papilionoideae): a new species from the Uzondo Plateau of Tanzania. Kew Bulletin 71:12. DOI 10.1007/S12225-016-9621-1

Type

Type: Tanzania, T4, Mpanda Distr., 63 km on the Uvinza - Mpanda road, 5°32'S, 30°33'E, fl. & fr. 20 May 1997, Bidgood, Sitoni, Vollesen & Whitehouse 4085 (holotype K; isotypes BR, C, DSM, EA, MO, NHT, P, UPS).

Morphology General Habit

Shrub, 0.5 - 1 m high.

Morphology Stem

Stem densely silvery-sericeous, blackened in places (possibly caused by smut); older stems glabrescent, red-brown in colour.

Morphology Leaves

Leaves 3- or 5- foliate; leaf-rachis (0.5 -) 0.7 - 1(- 1.4) cm long including petiole (0.3 -) 0.5 - 0.7 cm long; leaflets oblanceolate, attenuate at base, obtuse or rounded at apex, occasionally truncate-emarginated with an occa­sional mucronate tip, terminal leaflets 2 - 3 (- 3.9) x 0.5 - 1.2 cm; lateral leaflets 1.9 - 2.9 x 0.4 - 0.9 cm; discolorous, green and glabrous above except for a few scattered hairs along midrib, silvery-sericeous beneath with the outline of the principle veins still visible, with occasional golden coloured hairs along midrib.

Morphology Leaves Stipules

Stipules narrowly triangular up to 5 mm long.

Morphology Reproductive morphology Flowers

Flowers pedicellate in dense clusters in upper leaf axils; pedicels ± 3 mm long; bracts present narrowly triangular, 4 - 5 mm long, covered in silvery hairs.

Morphology Reproductive morphology Flowers Calyx

Calyx sericeous, silver to golden in colour, with darkened hairs on lower surface of calyx and calyx teeth, 9 - 12 mm long, tube ± 4 mm long, upper teeth 4 - 7 mm long slightly short than lower teeth 6 - 9 mm.

Morphology General Indumentum

Standard sericeous on the external surface, glabrous with scattered gland dots along the centre of the banner clustering towards apex on internal surface; 16 - 20 mm long, including a 4 - mm long claw, banner 11 - 15 mm long, 9 - 12 mm wide.

Morphology Reproductive morphology Flowers Corolla

Wing petals glabrous, 15 - 20 mm long including a 4 - 6 mm long slender claw, auriculate at base. Keel petals glabrous with scattered gland dots, 14 - 18 mm long including claw 4 - 6 mm long. Petals yellow to orange-brown (fading to white after anthesis).

Morphology Reproductive morphology Flowers Androecium Stamens Filaments

Filament sheath 12 - 16 mm long, free at apex for ± 3 mm, upper filament free for % its length; anthers 0.8 - 1 mm long.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary hairy.

Morphology Reproductive morphology Flowers Gynoecium Style

Style glabrous curved upwards, thickened at bend, penicillate.

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma falling early in fruit.

Morphology Reproductive morphology Fruits

Pod (1.7 -) 2.4 - 2.8 (- 3) cm long, ± 0.5 cm wide, silvery- sericeous, both sutures wavy, following outline of seeds, hairs on upper suture conspicuously darker.

Morphology Reproductive morphology Seeds

Seeds (2 -)3- 4, oval, 4 - 5 mm long, ± 3 mm wide, light brown in colour.

Distribution

Africa: Tanzania; only known from Mpanda District, from the Uzondo plateau.

Ecology

This species occurs on rocky outcrops and rock crevices within Brachystegia woodland or open grassland areas at an altitude of 1550 - 1700 m and is recorded as locally common.

Conservation

Tephrosia uzondoensis is known from a single location on the Uzondo Plateau, Mpanda District, Tanzania. Presently the plateau is largely undis- turbed and has a very low human population. However this region is dissected by the main north-south road of west Tanzania between Uvinza and Mpanda. Future plans to expand and grade the existing road could alter the current suitable habitat of this new Tephrosia species. Areas immediately surrounding this road could also be affected from increased road use from the gradually expanding population in western Tanzania due to collection ofwood for fire and construction from nearby settlements which would result in habitat degradation. Using the IUCN Categories and Criteria (2001), the species is therefore assessed as Vulnerable: Vu D2, due to a very small range, with an EOO of 0.459 km2,anAOOof8km2 based on a cell width of 2 km as recommended by the IUCN (2014) (Geocat; http://geocat.kew.org) and future plausible threats of road expansion and increased disturbance from a rising population associated with this highway.

Note

According to Brummitt (2007) this new species belongs to subgenus Tephrosia as it has a glabrous style with an apical penicillate tuft of hairs, an important character to observe when identifying Tephrosia confidently. T. uzondoensis is easily recognised within this group by its sericeous indumentum, its low number of leaflets, its dense pedicellate clusters of large yellow to orange flowers and its few-seeded fruits. Tephrosia uzondoensis belongs to subgenus Tephrosia as it is recognised by a glabrous style terminating in a penicillate tuft. It is easily distinguished by its number of leaflets; sericeous indumentum; flower length and number of seeds. T. uzondoensis most closely resembles T. richardsiae J. B. Gillett but is easily distinguished from this species by its fewer leaflets, being 3 or 5 (vs (3 -)5- 13 leaflets in T. richardsiae); its sericeous indumentum (vs pubescent to tomentose in T. richardsiae); its larger flowers 1.7 -2.1 cm long (vs 1.2 -1.8 cm long in T.richardsiae) and by its fewer seeds per capsule (2 -)3- 4(vs6- 9in T. richardsiae). T. uzondoensis also resembles T. tanganyikensis. However T. tanganyikensis belongs to subgenus Barbistyla making the resemblance between these species superficial. In addition to the differences in style characters that define the two subgenera, T. uzondoensis can be easily distinguished from T. tanganyikensis by its number of leaflets being 3 or 5 (vs 5 - 11 leaflets in T. tanganyikensis); its larger flowers 1.7 -2.1 cm long (vs ± 1.2 cm long in T.tanganyikensis) and by fewer seeds per capsule (2 - ) 3 - 4( vs 6 –7 in T. tanganyikensis).