Brachyotum seorsum Wurdack
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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
Latin Diagnosis - Trichomata minute sparseque aspera. Ramuli novelli obscure quadrangulati, cum petiolis pedunculisque dense brevi-strigosi. Petiolus 2-4 mm. Lamina 12-21 x 4-8 mm. elliptica apice hebeti-acuta basi acuta, nervis primariis 3 supra impressis subtus expressis, secundariis utrinque 8-15 supra occultis subtus expressis reticulatisque; supra dense tuberculato-strigulosa, tuberculis 5-7/mm.2 sed non regulariter in lineas dispositis basi 0.4-0.5 mm. diam. apice abrupte setiferis seto 0.3-0.5 mm. longo; subtus densissime strigulosa. Flores plerumque 5-meri saepe terni, flore in medio dichasii interdum aborto; pedunculus gracilis nutans 10-20 x 0.5 mm., bracteolis ad basim dichasii 2-4 x 0.3-0.4 mm. linearibus valde caducis supra glabris subtus strigulosis. Pedicellus sub bracteolis 0.5-10 mm. longus dense strigulosus super bracteolis 3~6 mm. longus glandulosohirsutus; pedicelli pedunculique bracteolae eaedem. Hypanthium 5-6 x 4.5-6 mm., medio 0.3 mm. crassum, modice glanduloso-hirsutum, pilis 8-10/mm.2 plerumque basibus expansibus apice abrupte setiferis seta 0.4-0.7 mm. longa glandulifera cum pilis paucioribus (40%) appressis non-glandulosis intermixtis. Sepala 5-6 x 3.5-4 mm. lanceolata apice anguste acuta basi 0.5-0.7 mm. cohaerentia, sinu lato rotundato. Petala 10-11 x 7-9 mm. asymmetrice obovata apice oblique truncata, ciliis glanduliferis 0.1-0.7 mm. Filamenta 5"5.5 mm.; antherae 5-5.5 mm.; connectivum basi antherae ab anthera non liberum sed cum papilla juxtim basim 0.1-0.15 mm. longa. Stylus 15-18 x 0.5-0.6 mm., per 5-7 mm. exsertus. Ovarium 4.5-5 x 2.5-3 mm. apice per 1.5-2 mm. setulis conicis appressis glanduliferis modice vestitum, lobis apicalibus super loculos 0.2-0.3 mm.
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Discussion
Type Collection and Locality: Camp E-5161 (HOLOTYPE NY); Ecuador, Prov. Azuay, paramo and subparamo area north and northwest of Paramo del Castillo, about 6-8 km. north-northeast of Sevilla de Oro, 10000-11000 ft. elev., 31 Aug. 1945. "Straggling shrubs to 4 m. (lower on paramo but just coming into bud). Lvs deep green above, pale-ochraceous below. Hypanthium dull crimson, pubescence nigrescent. Corolla narrowly urceolate in outline at anthesis; body of petals suffused with pink, veins deep red, margins greenish-yellow." Known only from the type collection.
An analysis of the floral patterns in this species is presented in the introduction to this revision and in Figure 23. S. seorsum is related to B. angustifolium and to B. rostratum. From the latter species, it may be differentiated by the linear early-caducous peduncular bracteoles, the somewhat different leaf-shape, and the generally wider sepalar sinuses with the lobes tapering evenly to the apices rather than tending to be oblong and less acute. While having other single characters in common with various elements assigned to B. rostratum, the combination in B. seorsum gives an appearance quite distinct from any of these elements. For example, in none of the specimens of B. rostratum does there appear the combination of strictly appressed non-glandular pubescence below the pedicellar bracteoles and patent gland-tipped trichomes only above these bracteoles. The tubercles on the older leaves of specimens of the Peruvian species tend to become discrete, exposing the epidermis, but in B. seorsum, the older leaves are still completely covered with tubercles. The secondary veins are never as obviously reticulate in B. rostratum as in the Ecuadorian species.