Brachyotum tyrianthinum J.F.Macbr.
-
Authority
Wurdack, John J. 1953. A revision of the genus Brachyotum (Tibouchineae-Melastomataceae). Mem. New York Bot. Gard. 8 (4): 343-407.
-
Family
Melastomataceae
-
Scientific Name
-
Description
Species Description - Trichomes moderately but minutely scabrid. Branchlets obscurely quadrangular, moderately to densely long-strigulose to strigose, tardily glabrescent. Petiole (1-)3-6 mm. Blade 10-30 x 6-14 mm., narrowly ovate to elliptic with the apex acute or blunt-acute and the base broadly acute to subtruncate, the 3 primaries narrowly impressed above and elevated below, the 8-12 pairs of secondaries mostly invisible above and lightly elevated below; above moderately short-strigose, the hairs (3-)5-7(-10)/mm.2 with their basal 1/4-1/2 adherent and not abruptly expanded; below densely long-strigulose on the primaries, moderately to sparsely hirsutulous or loose-strigulose on the surface (3-)7-ll/mm.2, the glands mostly solitary 12-30/mm.2 Flowers 4-5-merous, the 4-merous ones usually predominant, solitary on short lateral leafy branchlets in opposite upper leaf axils. Pedicel 2-5 mm. above the last somewhat reduced (3-10 x 1-4 mm.) persistent leaves (bracteoles ?). Hypanthium 4.5-6 x 4-5 mm., 0.3-0.5 mm. thick medianly, sparsely to moderately strigose, the fine hairs 8-11/mm.2 and to 1.5-3.5 x 0.2-0.3 min. Sepals 6.5-9 x 3-4.5 mm., oblong-ovate to lanceolate with the apices acute, inside sparsely strigulose on the apical 1/5-1/2. Petals deep purple, 12-17 x 9-14 mm., obovate and sometimes slightly asymmetrical with the apices very broadly obtuse,the gland-tipped cilia 0.1-0.2 mm. (the terminal few to 0.4-0.8 mm.). Filaments 4-5 mm.; anthers 4.5-6.5 mm.; connective at anther base 1-1.7 mm., free of the anther 0.3-0.7 mm., the ventral lobing 0.1-0.2 mm. Style 18-21 x 0.4-0.7 mm., exserted 5-6 mm. Ovary 6.5-7 x 3.4-4 mm., sparsely to moderately longstrigulose on the apical 2-3.5 mm.y the apical lobes 0.7-1 mm. above the locules.
Distribution and Ecology - Distribution: central to northern Peru, alt. 2750-4000 m.
-
Discussion
Type Collection and Locality: Macbride & Featberstone 1438 (HOLOTYPE F; isotypes G-DEL, S, US); Peru, Dept. Huanuco, Mito, alt. 2750 m.
Type Photograph: F63425 (holotype).
Vernacular Names: Cachis (Macbride & Featberstone 1438). All of the 17examinable flowers in the type collection were 4-merous, as were all 15 in Scolnik 1323; 1 of 10 flowers in Sandeman 5109, 2 of 6 in Lobb s.n., 9 of 15 in Macbride & Featberstone 2092, and 5 of 5 in Sawada P89 were 5-merous. Aside from mery, the species is quite uniform morphologically, although an occasional flower has the sepals glabrous within.
Aside from its immediate relatives, B. tyrianthinum may be related to B. rosmarinifolium, the roughened pubescence being a possible indication of such a linkage. It is also somewhat reminiscent of B. strigosum, which however has smooth hairs, differently shaped sepals, much stouter hypanthial pubescence, larger and more deeply divided connective prolongation, and smaller apical ovary lobes.