Brachyotum jamesonii Triana
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Authority
Wurdack, John J. 1953. A revision of the genus Brachyotum (Tibouchineae-Melastomataceae). Mem. New York Bot. Gard. 8 (4): 343-407.
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Family
Melastomataceae
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Scientific Name
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Description
Species Description - Trichomes smooth, slender. Branchlets obscurely quadrangular, sparsely to moderately strigulose. Petiole 2-6 mm. Blade 6-12(-16)x 3-6 mm., lanceolateelliptic to ovate with the apex bluntly acute and the base broadly acute to obtuse, the 3 primaries impressed above and elevated below, the secondaries more or less obsolete; above sparsely strigulose, th'e hairs (2-)4-7(-9)/mm.2 with their basal 1/4-1/2 adherent; below sparsely loose-strigulose to hirsutulous, the surface hairs 6-9/mm.2 and each subtended by a cluster of glands. Flowers constantly 4-merous, ternate on short lateral or terminal branches with each flower closely invested by 2 persistent bracts and the dichasium invested by 2 similar bracts which are inserted at the base of the dichasium, or less frequently solitary and invested by 4 bracts; peduncle 3-15 mm. above the last leaves and 1-2 mm. diam., cernuous. Bracts elliptic to ovate with the apices acute to rounded, 5-9-nerved, outside centrally moderately strigulose but marginally nearly or quite glabrous; peduncular bracts (in ternate inflorescences) 9-18 x 4.5-7 mm.; pedicellar bracts 6-9.5 x (3.5—)5—7.5 mm., the pedicel 2-4 mm. long below them, 0-1 mm. above. Hypanthium 5-8.5 x 4-5 mm., 0.2 mm. thick medianly, moderately to densely strigose, the hairs 5-12/mm.2 and to 2.5"3.5 mm. long. Sepals 3-5-6.5 x 3-6 mm., ovate to oblong-ovate with the apices broadly acute to obtuse, united at bases 0.2-0.4 mm. and sometimes slightly imbricate. Petals deep purple, 14-16 x 11-15 mm., obovate and slightly asymmetrical with the apices obtuse to rounded, the gland-tipped cilia 0.1-0.3 mm. Filaments 2.5-5 mm.; anthers 3-6.5 mm.; connective at anther base 0.8-1.5 mm., free of the anther 0.3-0.8 mm., the ventral lobing 0.2-0.4 mm. Style 17-28 x 0.4-0.6 mm., exserted 4-10 mm. Ovary 5-6.5 x 2.5-3.5 mm., moderately short-strigulose on the apical 2-3.5 mm., the apical lobes 0.7-1.4 mm. above the locules.
Distribution and Ecology - Distribution: central Ecuador, alt. 3000-4000 m.
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Discussion
Type Collection and Locality: Spruce 6031 (HOLOTYPE K; isotypes BR, G, BOIS, G-DEL, GH, NY, P, W); Ecuador, southeastern Prov. Chimborazo near Prov. Canar border, "in m. Azuay, loco Runa-rupashca, 12,000 p. Aug. 1859" (fide holotype).
Type Photographs: Gleason 87-1 (isotype at K); F25863 (isotype at G-DC). Distribution: central Ecuador, alt. 3000-4000 m.
Chimborazo: Pangor and "Huangopud," Lehmann 5794 (F, GH, K, S, US). Canar: near Canar, Rose & Rose 22765 (GH, NY, US); Cerro Bueran, Fosberg & Giler 22648 (NA, NY); Pillzhum, Jameson 22 (GH). Azuay: "Toreador" between Molleturo and Quinoa, Steyermark 53193 (F, NY); along Rio Matadero west of Cuenca, Camp E-1998A (NY), Camp E-1998B (NY); Paramo de Tinajillas, Camp E-2278 (NY); near Nabon, Rose & Pachano & Rose 23003 (US). Without locality: "Perou," Bonpland s.n. (P).
The number of the type collection was misprinted as "6081" in the original publication.
S. jamesonii may be distinguished from its near relative, B. confertum, by its constantly 4-merous flowers, usually broadly acute-tipped innermost pair of floral bracts, less densely pubescent hypanthium, with the hairs whitish rather than tawny to yellowish, more acute sepals, and non-glandular ovary hairs. Some flowers in Lehmann 5794 have early-caducous glandular tips on the hypanthial hairs.