Solanum savanillense
Citation:
Repert. Spec. Nov. Regni Veg. 12: 66 (1912).
Type:
Ecuador. Zamora-Chinchipe: Tambo de Savanilla, 18 December 1876, André 4565 (holotype, K).
Last edited by:
Knapp, S.
Written by:
Knapp, S. & T. Helgason
Habit:
Slender, wand-like shrub to 1.2 m tall. Stems ca. 7 mm in diameter, fleshy and somewhat translucent, completely glabrous or with a few scattered uniseriate trichomes near the somewhat swollen nodes, the nodes occasionally dark purple, usually the stems green without conspicuous lenticels when dry.
Sympodial structure:
Sympodial units unifoliate.
Leaves:
Leaves 10-17 x 7-16 cm, pinnate, with 1-2 pairs of leaflets, occasionally purple abaxially, sparsely pubescent abaxially with simple uniseriate trichomes ca. 0.5 mm long, 4-5-celled, these denser along the veins, more densely pubescent adaxially, the trichomes ca. 1 mm long and 8-10-celled; petiole 3.5-4 cm long; rachis of leaf minutely winged, sparsely pubescent with simple, uniseriate trichomes ca. 0.05 mm long; lateral leaflets obovate, 10-12.5 x 3-5.5 cm, the base attenuate, the apex acuminate; petiolule 0.5-0.8 cm lost; basal leaflets obovate, smaller, 5-10.5 x 1.7-4.2 cm, the lamina often narrower on the acroscopic side of the leaflet, the blade attenuate, the apex acuminate; petiolule ca. 0.5 cm; terminal leaflet obovate, broader than any of the laterals, 6-16 x 3-7 cm, the base attenuate, the apex acuminate; petiolule ca. 1 cm long.
Inflorescences:
Inflorescences 1-3 cm long, simple, up to 3 rachis arising from a single leaf axil, bearing flowers only in the distal half, with only 1 or 2 flowers open at a time, but with ca. 10-15 scars, sparsely pubescent with simple, uniseriate trichomes like those of the leaves. Buds ca. 0.5 cm in diameter, globose to ovate, strongly exserted from the calyx tube. Pedicels at anthesis 0.5-0.7 cm long, ca. 0.5 mm in diameter, nodding, glabrous or minutely pubescent.
Flowers:
Flowers with the calyx tube 1.5-2 mm long, conical, the lobes ca. 0.5-1 x 0.5 mm, deltate, splitting irregularly at the sinuses, with a prominent terminal projection, sparsely pubescent with trichomes like those of the inflorescence, the trichomes denser on the tip of the lobes; corolla 10-12 mm in diameter, white or purple (see commentary), lobed nearly to the base, the lobes planar at anthesis, densely papillate at the tips and margins; anthers 2.5-3 x ca. 1 mm, poricidal at the tips, free portion of the filaments ca. 0.5 mm long, the filament tube minute; ovary conical, glabrous; style 5-6 mm long, densely short-pubescent in lower half; stigma clavate.
Fruits:
Fruit an elongate, conical green berry, 1-2 x ca. 1 cm, the surface lightly rugose; fruiting pedicel 1-1.2 cm long, erect.
Seeds:
Seeds ca. 3.0-2.5 mm, ovoid-reniform, bright green, ca. 20 per fruit; epidermal cells highly sinuous and irregular, with anticlinal thickenings but without projections.
Chromosome number:
Not known
Distribution:
S Ecuador in cloud forest, 2300-3000 m.
Phylogeny:
Solanum savanillense is a member of the Solanum mite group of section Pteroidea in the Potato clade (Bohs, 2005). Based on morphology (Knapp & Helgason, 1997), S. savanillense is sister to S. uleanum.
References:
Knapp, S. & T. Helgason 1997. A revision of Solanum section Pteroidea Dunal: Solanaceae.
Bull. Nat. Hist. Mus. London, Bot. 27: 31-73.
Bohs, L. 2005. Major clades in Solanum based on ndhF sequences.
Pp. 27-49 in R. C. Keating, V. C. Hollowell, & T. B. Croat (eds.), A festschrift for William G. D’Arcy: the legacy of a taxonomist. Monographs in Systematic Botany from the Missouri Botanical Garden, Vol. 104. Missouri Botanical Garden Press, St. Louis.
Solanum savanillense is superficially similar to many of the other pinnate-leaved members of section Pteroidea. It can be distinguished easily, however, by its larger flowers, more elliptic, slightly less rugose fruits and its tall stature. This last character is impossible to ascertain from herbarium sheets, but in the field S. savanillense is quite distinct from S. mite or S. conicum, the only other members of the group to attain such sizes. The leaves of S. savanillense are more pubescent adaxially than abaxially, the reverse of the pattern in other members of the group. In 5-foliolate leaves of S. savanillense, the basal pair of leaflets is conspicuously smaller than the other pair, a characteristic not found in other species in the section.
In Parque Nacional Podocarpus in southern Ecuador Solanum savanillense is polymorphic for both flower and stem colour but the leaves are uniformly green, never tinged with purple as occurs in polymorphic populations of S. anceps (for example). In populations collected ascending the Nudo de Cajanuma, groups of plants were either green-stemmed and white-flowered or with purple nodes and purple-flowered. This polymorphism may be purely genetic in origin. Solanum savanillense grows in understory in deep shade, and plants of both colour morphs were found side by side, indicating little ecological control of this character.
Bitter, in describing Solanum savanillense, stated that the type was collected in Costa Rica. André never collected in Costa Rica, but was in southern Ecuador in December of 1876. The type specimen does not bear any annotation or other indication that it is from Costa Rica, so it is likely that Bitter either made a mistake transcribing label data or simply confused locality data from specimens he saw at K. André’s locality “Tambo de Savanilla” probably corresponds to the present-day village of Sabanilla in the province of Zamora-Chinchipe or to the pass on the Loja to Zamora road (3°38’S, 79°05’W), which lies within the Parque Nacional Podocarpus. In Ecuador, nudo means a pass and tambo a stopping place, usually a small town.