Solanum maternum (Solanaceae), a New Bolivian Relative of the Tree Tomato Lynn Bohs* and Ann Nelson Department of Biology, University of Utah, Salt Lake City, Utah 84112, U.S.A. *Present address: Department of Botany, Duke University, Durham, North Carolina 27708-0338, U.S.A.ABSTRACT.. A new species endemic to Bolivia, So-lanum maternum, is described. Solanum maternumbelongs to a group of taxa formerly recognized asthe genus Cyphomandra. Solanum maternum ismorphologically very similar to the tree tomato, So-lanum betaceum, and may be its closest wild rela-tive. The former genus Cyphomandra Sendtner en-compasses a group of about 30 species of shrubsand small trees with usually large, pendent fruits.The group is characterized by the presence of anenlarged connective region on the abaxial anthersurface; this structure may play a role in pollinationby secreting volatile compounds that attract maleeuglossine bees (Gracie, 1993; Sazima et al., 1993;Soares et al., 1989). Other characteristics of theCyphomandra group that occur in most, but not all,species include Prevost's architectural model, verylarge chromosomes, and gametophytic self-incom-patibility (Bohs, 1994). Recent molecular evidence indicates that theCyphomandra group is nested within Solanum(Bohs & Olmstead, 1997; Olmstead & Palmer,1992, 1997; Spooner et al., 1993), and all Cyphom-andra species have now been transferred or re-turned to Solanum (Bohs, 1995), where the first de-scribed species were placed. The infragenerictaxonomy of Solanum is currently under study andno infrageneric rank is consistently used at presentfor the Cyphomandra group. The monophyly of theCyphomandra group and the relationship of thisgroup to others within Solanum, particularly its pu-tative sister group, Solanum sect. CyphomandropsisBitter, are issues that need to be examined beforea taxonomic designation is made. Species of the Cyphomandra group have been ofinterest because many produce edible fruits thatare gathered from the wild or grown as minor crops.The most important in this regard is Solanum be-taceum Cavanilles, the tree tomato, which is fre-quently cultivated in Latin America and commonlysold in Andean markets. Solanum betaceum hasalso been an item in international commerce, usu-ally sold under the name "tamarillo." Until recent-ly, little was known about the place of origin of thetree tomato, which is usually regarded as being acultigen. A group of species from Bolivia has nowbeen identified as the closest wild relatives of S.betaceum, based on morphological and crossingdata (Bohs, 1991, 1994). The species describedhere is a new member of this species complex andbears great morphological similarity to S. betaceum.Evidence presented below indicates that the newspecies is interfertile with S. betaceum and with twoother members of the S. betaceum species complex.Solanum maternum Bohs, sp. nov. TYPE: Boliv-ia. Santa Cruz: Prov. Caballero, Siberia-El Empalme, 5 km entrando hacia Khara Huasi, carretera entre Comarapa-Cochabamba, 17�50'S, 64�43'W, 2300 m, 8-9 May 1992 (fl, fr), I. Vargas & E. Prado 1273 (holotype, NY; isotypes, DUKE, MO not seen, USZ not seen). Figure 1. Solano betaceo Cavanilles affine, a quo differt corollisalbo-purpureis, fructibus maturis luteis, pube paulo spars-iore, connectivis antherarum paulo latioribus. Small tree or shrub 1-4 m tall. Branches andpetioles moderately to densely puberulent withglandular and eglandular unbranched hairs lessthan 1 mm long. Leaf blades simple, unlobed, char-taceous, acuminate at apex, moderately puberulentadaxially, more densely so on veins, densely pu-berulent abaxially. Trunk leaves with blade ovate,19-34 cm long, 15-24 cm wide, length:width ratioca. 1.5:1, the base cordate with basal lobes 1-4 cmlong; petioles 11-22 cm long. Crown leaves 4 persympodial unit, the blade ovate, 6.5-21 cm long,5-14 cm wide, length:width ratio ca. 1-1.5:1, thebase cordate to auriculate with basal lobes 1-3 cmlong; petioles 2.5-11 cm long. Inflorescence un-branched or branched, ca. 20-60-flowered, 5-10cm long; peduncle 3-4 cm long; rachis 2-8 cmlong; pedicels ca. 15-20 mm long, 20-35 mm longin fruit, ca. 1-10 mm apart, articulated above the NovoN 7: 341-345. 1997.