Solanum imamense
Not known.
Solanum imamense is endemic to Madagascar, with a broad distribution range in the west, the south, and on the high central plateau; in the provinces of Mahajanaga, Antananarivo, and Toliara. It grows in open dry forest and forest edges; often growing on rocks; 900-1000 m.
None recorded.
Preliminary conservation status (IUCN 2014). Least Concern (LC). EOO 165,095 km2 (LC), AOO 40 km2 (EN). In common with other members of the ANS clade in Madagascar, Solanum imamense has a relatively wide distribution, resulting in an EOO indicating lack of immediate conservation concern. The paucity of collections, indicative of local rarity, coupled with the ongoing habitat threats in Madagascar, however, do indicate monitoring and further collection to assess local and regional rarity is necessary.
Solanum imamense is a fairly common liana or shrub with shallowly cordate or truncate leaves clustered towards tips of branches, large (to 3 cm in diameter) violet or purple flowers, and large anthers 4-5 mm long. The pubescence of dendritic trichomes up to 0.3-0.5 mm long is visible with the naked eye on the petioles, pedicels, inflorescences and abaxial sides of the leaves (Figs. 1B, 2B).
Solanum imamense is morphologically similar and possibly closely related to S. betroka from southern Madagascar and S. sambiranense from northern Madagascar, and perhaps also the rare and poorly known S. ivohibe from the province of Fianarantsoa. Solanum imamense differs from S. betroka in its inflorescences with 7-13 (versus 1-3) flowers, larger floral parts, and leaves that are always entire (versus leaves that are frequently lobed). Solanum imamense can be distinguished from S. sambiranense by its ovate leaves 2.5-5 cm long (versus elliptic to obovate leaves 5-10 cm long) and looser dendritic trichomes 0.2-0.5 mm (versus less than 0.1 mm) long. Solanum imamense differs from S. ivohibe by its ovate leaves less than 5 cm long (versus elliptic to obovate leaves 5-7 cm long), cordate to short attenuate (versus long attenuate) leaf base, and calyx lobes more than 2 mm (versus less than 2 mm) long.
Solanum imamense has a broad ecological profile occurring occasionally in dry to mesic parts of the island in the western, central, and southern ecoregions (Humbert 1955; Faramalala 1988, 1995). In the southern part of its distribution range it is sympatric with S. betroka and in the northern part of the range with S. sambiranense.
Solanum imamense var. grandiflorum was accepted by Bitter (1917) but synonymised with Solanum imamense by D’Arcy and Rakotozafy (1994). It differs from the type variety by flower size and pubescence density, but the variation in both characters is continuous. The type specimens of both were collected by W. Bojer in central Madagascar. Solanum ankazobe was described on the basis of three collections, and was distinguished by its small leaves, smaller calyx tube, irregular tearing of the calyx and wider ovary. The type collection of S. ankazobe (Perrier de la Bâthie 9615) has leaves that fall within the range of variation in S. imamense, while other specimens cited have smaller floral parts (Perrier de la Bâthie 9577 and 9579). We consider these specimens to fall within the range of variation represented in S. imamense and treat S. ankazobe as a synonym.