Solanum inaequiradians
Citation:
Notizbl. Bot. Gart. Berlin-Dahlem 12: 90. 1934.
Type:
TANZANIA. Morogoro: Uluguru Mtns., NW side, 1150 m, 18 Sep 1932, H. F. Schlieben 2707 (holotype: B! [B100165207]; isotypes: BM! [BM000847754], BR! [BR0000006289218], G! [G00343574], LISC! [LISC011340], M! [M0105599], P! [P00344045], S! [S-G-5695], Z! [Z-000027792, Z-000027793]).
Last edited by:
Sandra Knapp (May 2014)
Written by:
Maria S. Vorontsova & Sandra Knapp
Habit:
Scandent shrub, ca. 0.5 m, prickly. Young stems terete, densely stellate-pubescent and prickly, with porrect, subsessile trichomes, the stalks to 0.15 mm long, the rays ca. 8, 0.1-0.2 mm long, the midpoints (0.5-)1.5-2.5(-3) mm, the prickles 2-4 mm long, 0.8-1(-3) mm wide at base, curved, sometimes straight and reflexed, deltate, conical to somewhat flattened, yellow-orange, glabrous, spaced 1-5 mm apart; bark of older stems glabrescent to moderately stellate-pubescent, reddish gray-brown.
Sympodial structure:
Sympodial units plurifoliate.
Leaves:
Leaves simple, the blades 7-10(-13) cm long, 3.5-4.5(-6) cm wide, ca. 2 times longer than wide, ovate, chartaceous, drying discolorous, yellow-green; adaxial surface moderately stellate-pubescent, appearing villous, the trichomes with bulbous bases, the midpoints 1.5-2.5 mm long; abaxial surface moderately stellate-pubescent, with porrect, sessile or stalked trichomes, the stalks to 0.15 mm long, the rays 6-8, 0.2-0.35 mm long, the midpoints 1-2 mm long, with 0-30 prickles on both surfaces; the primary veins 4-5 pairs, the tertiary venation faint, branching; base truncate to cuneate; margins entire to shallowly lobed, the lobes 2-4 on each side, 0-1 cm long, extending to 1/3(-1/2) of the distance to the midvein, deltate to rounded, apically rounded to acute; apex acute or somewhat long-acuminate; petiole 1-2.5 cm long, 1/5-1/4 of the leaf blade length, densely stellate-pubescent, with 0-5 prickles.
Inflorescences:
Inflorescences apparently terminal or lateral, 3-5 cm long, not branched, with 2-6 flowers, 1-4 flowers open at any one time, densely stellate-pubescent, with 0-2 prickles; peduncle absent; pedicels ca. 0.8 cm long, erect, articulated at the base, densely stellate-pubescent, with 0-5 prickles; pedicel scars spaced ca. 2 mm apart.
Flowers:
Flowers 5-merous, usually all perfect, occasionally with a few short-styled staminate flowers at the inflorescence apex. Calyx 7-9 mm long, densely stellate-pubescent, with 0-10 prickles, the lobes 4-6 mm long, narrow-deltate, apically thin-acuminate. Corolla 1.7-2 cm in diameter, mauve to purple, stellate, lobed for ca. 4/5 of the way to the base, the lobes ca. 10 mm long, 2-1.5 mm wide, oblong, reflexed or spreading, densely stellate-pubescent abaxially, the trichomes porrect, sessile, the rays ca. 8, 0.05-0.15 mm long, the midpoints 0.7-1 mm long. Stamens equal, with the filament tube ca. 0.7 mm long, the free portion of the filaments ca. 1 mm long; anthers ca. 7 mm long, connivent, tapering, poricidal at the tips. Ovary glabrous; style ca. 1.2 cm long in long-styled flowers, slender, gently curved, glabrous.
Fruits:
Fruit a spherical berry, often elongate when young, 1-2 per infructescence, 1.2-1.4 cm in diameter, the pericarp smooth, dark green with pale green and cream markings when young, orange to bright red at maturity, glabrous; fruiting pedicels 2-2.5 cm long, 0.3-0.4 mm in diameter at base, woody, pendulous, with 0-15 prickles; fruiting calyx lobes elongating to 10-12 mm long, ca. 1/2 the length of the mature fruit, with 0-10 prickles.
Seeds:
Seeds ca. 20-30 per berry, 2.8-3.2 mm long, 2.5-2.8 mm wide, flattened-reniform, dull yellow to orange-brown, the surface smooth or with raised outlines of cells or small pits.
Chromosome number:
Not known
Distribution:
Endemic to Tanzania, known only from the Morningside region of the Uluguru Mountains, growing in forest at 1500-2000 m elevation.
Phenology:
Flowering and fruiting from September to April.
Phylogeny:
Solanum inaequiradians is a member of the Old World clade within subgenus Leptostemonum (Levin et al., 2006); within that group it belongs to the large unresolved Anguivi Grade, and appears to be related to S. ruvu and S. lamprocarpum (Vorontsova et al. 2013).
References:
Levin, R.A., N.R. Myers, & L. Bohs 2006. Phylogenetic relationships among the "spiny" solanums (Solanum subgenus Leptostemonum). Amer. J. Bot. 93: 157-169.
Vorontsova, M. S., S. Stern, L. Bohs, and S. Knapp. 2013. African spiny Solanum (subgenus Leptostemonum, Solanaceae): a thorny phylogenetic tangle. Bot. J. Linn. Soc. 173: 176-193. doi:10.1111/boj.12053
Werdermann, E. 1934. Solanaceae. In Neue und seltene Arten aus Östafrika, leg. H.J. Schlieben, VI, ed. J. Mildbraed. Notizbl. Bot. Gart. Berlin-Dahlem 12: 90-94.
Solanum inaequiradians occurs within the distribution range of S. zanzibarense. It is similar to S. zanzibarense in its small flowers with narrow corolla lobes, leaf shape, and climbing habit; it can be distinguished by its long-attenuate calyx lobes exceeding the corolla in bud, 7-9 mm long in flower, and 10-12 mm long in fruit (versus calyx lobes shorter than corolla in bud and 2-4 mm long in flower and fruit in S. zanzibarense), and trichomes with midpoints 1.5-3 mm long (versus trichomes with midpoints reduced or up to 0.2 mm long in S. zanzibarense). Solanum inaequiradians can also be confused with the morphologically similar S. lamprocarpum, S. stipitatostellatum, and S. usaramense. Solanum stipitatostellatum is morphologically similar to S. inaequiradians with its acuminate leaves, dense indumentum and trichomes with midpoints that are sometimes elongated. Jaeger (1985) suggested the possibility of including S. inaequiradians within S. stipitatostellatum, but S. inaequiradians is clearly distinguished by its long calyx lobes (versus calyx lobes shorter than the corolla in bud, 4-6 mm long in flower and 5-8 mm long in fruit in S. stipitatostellatum), and trichomes with long midpoints (versus midpoints that are usually shorter than the rays and never extend beyond 0.7 mm in S. stipitatostellatum). Solanum inaequiradians is reminiscent of S. usaramense with its small hooked stem prickles and discolorous leaves, and similar to S. lamprocarpum with its elongated midpoints; it can be distinguished from both of these by its long calyx lobes.
Although Werdermann (1934) did not cite a herbarium in which he saw Schlieben 2707 we have assumed material in Berlin represents holotypes for his names, as he worked only in that herbarium; this is one of the few holotypes of African solanums from Berlin that is still extant. Richard Lester annotated some of the BR duplicates (incorrectly) as "lectotype", but never published.