Solanum malacothrix S.Knapp
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Authority
Knapp, Sandra D. 2002.
section (Solanaceae). Fl. Neotrop. Monogr. 84: 1-404. (Published by NYBG Press) -
Family
Solanaceae
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Scientific Name
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Type
Type. Mexico. Guerrero: Distr. Mina, Aguazarca, 5 May 1937, Hinton et al. 10418 (holotype, NY; isotypes, K, LL, MEXU, U, US)
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Description
Species Description - Shrubs 2-3 m tall; young stems and leaves densely pubescent with soft uniseriate trichomes ca. 0.5 mm long; older stems remaining pubescent, not glabrate, grayish-brown. Sympodial units difoliate, geminate, the minor leaf often deciduous. Leaves narrowly ovate, widest just proximal to the middle, sparsely pubescent above with uniseriate trichomes, these denser on the veins, densely pubescent below with soft uniseriate trichomes 0.5-0.75 mm long, the epidermis barely visible in dry specimens; major leaves 10-16 x 2.5-5 cm, with 11-14 pairs of main lateral veins, these raised and pubescent above, prominent and yellowish beneath, the apex acuminate, the extreme tip rounded, the base attenuate; petioles channeled above, 7-8 mm long; minor leaves differing from the major ones only in size, 6.5-11 x 1.5-3.5 cm, the apex acuminate, rounded at the very tip, the base attenuate; petioles 6-8 mm long. Inflorescences opposite the leaves, simple, 1-1.5 cm long, 10-30-flowered, pubescent along the rachis with uniseriate trichomes like those of the stems and leaves; pedicel scars closely spaced, but not overlapping, occasionally ca. 0.5 mm apart. Buds globose, the corolla soon exserted from the calyx and the buds then ovoid to ellipsoid. Pedicels at anthesis deflexed, 8-9 mm long, tapering from the calyx tube to a slender base ca. 0.5 mm diam., with a few uniseriate trichomes ca. 0.5 mm long. Flowers with die calyx tube broadly cup-like, ca. 1 mm long, the lobes broadly deltoid, 0.5-1 mm long, with tufts of uniseriate trichomes on the tips of the lobes, otherwise sparsely pubescent with uniseriate trichomes like the rest of the inflorescence; corolla probably white, 0.8-1 cm diam., lobed nearly to the base, the lobes reflexed at anthesis, the tips and margins of the lobes minutely papillose; anthers ca. 2 x 1 mm, poricidal at the tips, the tips paler and slightly thickened, the pores teardrop shaped; free portion of the filaments ca. 0.5 mm long, the filament tube ca. 0.25 mm long; ovary glabrous; style straight, ca. 5 mm long; stigma a minutely papillose area at the tip of the style. Fruit and seeds not known; fruiting pedicels erect in immature fruit. Chromosome number not known.
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Discussion
Solatium malacothrix is most closely related and superficially quite similar to S. diphyllum, a widespread lowland Mexican species. Solanum malacothrix is distinctive in its long, soft leaf pubescence, which is unusual in the section; while S. diphyllum is completely glabrous. Solanum lasiocladum of Venezuela also possesses this type of leaf pubescence. It differs from S. malacothrix in its apiculate calyx lobes, larger flowers, and long-petioled leaves with acute apices, and I have not assigned it to any of the species groups. The mature fruits of S. malacothrix are not known, but in view of its overall similarity to S. diphyllum I would expect them to be brightly colored, borne on erect pedicels, and rather fleshy.
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Distribution
In the northwestern comer of the state of Guerrero, on the slopes of the Sierra Madre del Sur in the Rio Balsas drainage, in tropical deciduous forest or dry pine-oak woodland (“bosque tropical caducifolio” or “bosque de Quercus” of Rzedowski, 1978).
Mexico North America| Guerrero Mexico North America|