Solanum flaccidum
In forests and along forest margins and riversides from coastal Brazil inland to Paraguay, from 40-1800 m.
With its vining habit, pedicels inserted into tiny sleeves and terminal branched inflorescences, Solanum flaccidum is a member of the Dulcamaroid clade (sensu Weese & Bohs, 2007), but has not yet been included in molecular analyses.
Vellozo, J.M. da Conceiçao. 1827. Florae fluminensis icones figs. 1-156.
Senefleder, Paris.
Smith, L.B. & R.J. Downs 1966. Solanaceae.
In P.R. Reitz (ed.), Flora ilustrada Catarinense, fasc. SOLA: 1-321.
Carauta, J.P.P. 1973. The text of Vellozo’s Flora fluminensis and its effective date of publication.
Taxon 22: 281-284.
Mentz, L.A. & P.L. de Oliveira 2004. Solanum (Solanaceae) na região sul do Brasil.
Pesquisas, Bot. 54: 1-327.
Weese, T.L. & L. Bohs 2007. A Three-Gene Phylogeny of the Genus Solanum (Solanaceae)
Syst. Bot. 32(2): 445-463.
Solanum flaccidum is a relatively common species where it occurs, and in Brazil it occurs sympatrically with S. odoriferum, also a vining member of the Dulcamaroid clade. The two species can be distinguished by their leaf morphology (glabrous and shining in S. odoriferum, variously pubescent in S. flaccidum), calyx shape (truncate in S. odoriferum, lobed in S. flaccidum) and anther morphology. Solanum flaccidum has one anther with the filament much longer than the other four, while in S. odoriferum, the filaments are all equal throughout anthesis. In early anthesis in S. flaccidum, the filaments appear to be more or less equal, so care must be taken to examine fully mature flowers.
In Paraguay S. flaccidum is sympatric with S. uncinellum, which also has one anther borne on a longer filament. Solanum flaccidum has more rotate flowers than the latter species, and in general is less pubescent with simple, rather than dendritic, trichomes. The long filament in flowers of S. uncinellum is twice as long as the other filaments, while in S. flaccidum the long filament is less than twice as long as the others.
As with many species in this group, S. flaccidum has heteromorphic leaves, with simple and pinnatifid leaves borne on the same stems. Once a stem is flowering, it appears that the leaves are all simple, so very few collections have been made of plants with pinnatifid leaves. It may be, as with other species of this clade, that juvenile foliage is more likely to be pinnatifid than is foliage on reproductive shoots (see S. dulcamaroides).
In the absence of specimens (Carauta, 1973), lectypification of Vellozo names is best done using the plates from that work (Vellozo, 1831); they are distinctive and in this case have all the distinguishing features of the species (i.e., twining petioles and unequal anthers). Martius’ various names for this species all have many specimens cited; lectotypification will be complicated by the fact that most of these are un-numbered and are today mixed with specimens of other vining species from southeastern Brazil in many herbaria (e.g., S. laxum, S. amygdalifolium). Mentz & Oliveira (2004) did not find type specimens for Witasek’s two varieties in W; but it is likely that all Witasek’s types should be sought in WU instead (fide E. Vitek, pers. comm.).
Although the type of Solanum delilei was said to have been grown from Mexican seeds, the specimen at G has the unmistakably unequal anthers of S. flaccidum. Several sheets of Lhotsky 87 in G-DC have labels stating “Solanum uvareaifolium nob. 1819” in Dunal’s hand; this name was never published. The syntypes of S. fultum are a complex of mixed sheets of S. laxum and S. flaccidum. Lectotypification of this name will fix synonymy more firmly; usage has been mixed, but the M sheet (likely to have been used by Schrank) is S. flaccidum.
The type specimen of S. uncinellum var. atrosanguineum at P has the ellipsoidal anthers and rotate-stellate corolla of S. flaccidum, not the tapered anthers and deeply stellate corolla of the more widespread S. uncinellum.