Solanum imbaburense S. Knapp, 1989

Knapp, Sandra, 2013, A revision of the Dulcamaroid Clade of Solanum L. (Solanaceae), PhytoKeys 22, pp. 1-432 : 136-139

18. Solanum imbaburense S. Knapp , Bull. Brit. Mus. Nat. Hist. (Bot.) 19: 94. 1989 Figure 47

Type.

Ecuador. Imbabura: road Ibarra-Mariano Acosta, E of the pass, montane forest with large trees, 3500-3600 m, 0°20'N, 78°W, 9 Aug 1976, B. Øllgaard & H. Balslev 8567 (holotype: F; isotypes: AAU, BM [BM000072707], QCA, QCNE, MO [MO-5080092], NY [NY00172013]).

Description.

Shrubs ca. 2 m tall. Stems sparsely pubescent with white, dendritic trichomes, the branches of the trichomes short; leaf scars prominent, the stem strongly winged from the decurrent leaf bases; new growth glabrous and shiny except for a few dendritic trichomes on the revolute margins of the leaves. Bark of older stems reddish-brown, glabrate. Sympodial units plurifoliate, branching dichasial. Leaves simple, 3.5-6 cm long, 1-2 cm wide, narrowly obovate to elliptic, coriaceous, the adaxial surfaces glabrous and shiny, the abaxial surfaces glabrous, with a few dendritic trichomes on the revolute margins; primary veins 6-7 pairs, strongly impressed above; base attenuate, strongly decurrent on to the petiole and from there on to the stem; margins strongly revolute; apex acute, occasionally mucronate; petiole 2-4 mm long, strongly decurrent on to the stem, not twining. Inflorescences terminal, later in the fork of the branches, 4-6 cm long, narrowly pyramidal, branching 2-3 times, with 6-10 flowers sparsely pubescent with dendritic trichomes like those of the young stems; peduncle 1.7-3 cm long; pedicels 0.9-1.2 cm long, somewhat nodding at anthesis, tapering from a basal diameter of ca. 0.5 mm to an apical diameter of ca. 1 mm, densely pubescent with erect, dendritic trichomes, articulated at the base and inserted in a sleeve ca. 1 mm long; pedicel scars closely spaced and clustered at the inflorescence branch tips. Buds obovate to elliptic, the corolla strongly exserted from the calyx tube. Flowers all perfect, 5-merous. Calyx tube ca. 3 mm long, conical, the lobes 4-5 mm long, long-triangular to acuminate, the abaxial surfaces of the lobes sparsely dendritic pubescent along the margins, the adaxial surfaces glabrous or with a few minute, glandular trichomes. Corolla 2.5-3 cm in diameter, violet, lobed 3/4 of the way to the base, the lobes 14-15 mm long, 7-8 mm wide, planar at anthesis, the abaxial surfaces of the lobes densely pubescent with dendritic trichomes, these denser along the veins, adaxi ally with dendritic trichomes along the petal midveins. Filament tube absent; free portion of the filaments ca. 2 mm long, glabrous; anthers ca. 4.5 mm long, 1.5 mm wide, loosely connivent, poricidal at the tips, the pores becoming slit-like with age. Ovary glabrous; style 8-9 mm long, glabrous; stigma bilobed, the surface minutely papillose. Fruit a globose berry, 1.1-1.2 cm in diameter, black when ripe, with thin pericarp; fruiting pedicels 1.8-2 cm long, ca. 1 mm in diameter at the base woody, erect. Seeds ca. 9 per berry, 3.5-4 mm long, 3.5-4 mm wide, flattened and round in outline, the surfaces minutely pitted. Chromosome number: not known.

Distribution

( Figure 48 ). Endemic to N Ecuador; from 3500-3600 m.

Ecology.

Moist forests, cloud forests.

Conservation status.

Data Deficient (DD); collections too few for assessment. That the species has not been re-collected in 35 years indicates it is certainly of conservation concern and exploration of the type locality to assess its health is a priority.

Discussion.

Solanum imbaburense is superficially similar to Solanum stenophyllum and Solanum ruizii , but differs from them in its lax dendritic pubescence, particularly on the inflorescence, its glabrous, coriaceous leave with strongly revolute margins and in its extremely long-acuminate calyx lobes. Some populations of Solanum stenophyllum have some glabrous individuals, but unlike Solanum imbaburense , these always possess at least some tree-like trichomes on the new growth.

Specimens examined.

Known only from the type.

Figures

Figure 47. Solanum imbaburense S. Knapp. (A-C drawn from Ollgaard & Balslev 8567). Reproduced from Knapp (1989) with permission of the Natural History Museum Botany Library. Illustration by Margaret Tebbs.

Figure 48. Distribution of Solanum imbaburense S. Knapp