Monographs Details: Comolia serpyllacea Wurdack
Authority: Maguire, Bassett & Wurdack, John J. 1958. The botany of the Guayana Highland--Part III. Mem. New York Bot. Gard. 10: 1-156.
Family:Melastomataceae
Description:Latin Diagnosis - Inter eongenera habitu foliis staminibusque bene distinctis. Caules repentes lignosi rubri vel brunnei quadrangulares, cum pilis rubris vel brunneis flexuosis 1-1.5 mm longis densiuscule vestiti. Folia breviter (0.3-0.8 mm) petiolata; lamina 2.5-4 X 1-1.5 mm, plana elliptica vel paulo ovatoelliptica apice acuta et brevissime (0.1 mm) setuloso-mucronulata basi acuta uninervia, margine integerrima vel apicem versus utrinque 1—2-dentata dentibus unisetosis, g'labra vel apicem versus supra cum setis 1—3 appressis ca. 0.5 mm longis. Flores in ram is lateralibus solitarii, pedicellis supra bracteas 4-6 mm gracili-setosis. Hypanthium 3.2-3.6 X 2.3-2.5 mm, modice (3-5/mm2) glanduloso-setosum, setis ad 1 mm longis. Sepala supra torum 0.5 vm coalita. lobis 2.3-2.7 X 1-2 mm, oblongis apice late acutis extus glabris, marginibus et intus apicem versus sparse glanduloso-setosis. Petala 13-14.5 X 10.2-10.7 mm, obovata apice rotundata marginibus apicem versus sparse glanduloso-ciliolatis. Stamina glabra in forma isomorphica, antheris rectis apice subulatis minute uniporosis. Stamina maiora: filamenta 4.2-4.5 mm; antherae 2.8-3.6 mm. connectivo sub loculis 0.5-0.7 mm producto ventraliter vix (0.2 mm) bilobato. Stamina "inora-. filamenta 3.5-3.7 mm; antherae 2.4-3.0 mm, connectivo sub locjlis 0.3-0.5 mm producto ventraliter imnersqicue bilobato. Ovarium slabrum biloculare multiovulatiru ; stylus glaber 7-8 X 0.2-0.4 mm apicem versus e-radatim contractus; stisira pvnetiforme.

Distribution and Ecology - Paratypes: repent, mat-forming, petals magenta, anthers yellow, common on ledges on upper escarpment face, elev. 1300-1700 m, Cerro Huachamacnri, Rio Ounucunuma, Terr. Amazonas, Venezuela. Dec 5, 1 1950. Maguire, Cowan & Wurdack 29886: creeping in liverworts, netals pink, anthers yellow, upper escarpment slopes east of Camp 3, elev. 17(10 m. Cerro de la Neblina, Rio Vatun, Terr. Amazonas, Venezuela, Dec 24. 1953, Maguire, IVnrdack & Bunting 36811; idem, Dec 27, 1953; 36923; idem, elev. 1600 m, Jan 24, 1954, 37372.

Discussion:

The habit and nearly isomorphic stamens of C. serpyllacca preclude any consideration of sect. Dicrananthera of the genus Arisanthrra. Within Comolia, the Neblina species would be placed in Sect. 1 near C. Icptophijila (Ronpl.). Xaiid. because of the bilocular ovary and one-nerved leaves; C. leptophylla has a different habit, glabrous branches, much longer leaves, and stamen connective conspicuously prolonged ventrally. The stamens of C. serpyllacea are more reminiscent of C. montana Gleason and C. coriacea (Ueason although the basal connective thickening of those species is more pronounced. The small leaves are somewhat reminiscent of those of C. sertularia (DC.) Tr. but the habit, curved leaf-margins, glandular-puberulent branches and lower leaf-surfaces, long stamen connectives, and quadrilocular ovary of the Brazilian species make the resemblance seem superficial. The Brazilian genus Fritzschia has similar leaves and stamen connective prolongation but glabrous stems, foliage, and hypanthium, more abruptly truncate anthers, and 4-locular ovary.

Vegetative variability in savanna plants is usually quite great; dimensional floral variation is also significant. The latter type of variability is certainly influenced by the flowering period, with the later flowers on a single plant often being much smaller; this phenomenon can be seen wherever a large stand of Rhynchanthera serndata (Rich, ex Bonpl.) DC. or Pterogastra minor Naud. is found. In Tiboiichina spruccana Cogn., the last few flowers on a plant often are semiabortive with distorted petals and sterile stamens.

Gleason has several times suggested the possibility of heterostyly in Andean Miconia of sect. Cremanium. Such floral diversity, if finally recognized taxonomically will lead to the synonymy of many species of Miconia. For specific limits in the rare genus Pachyloma, it has seemed necessary to recognize a floral latitude uncountenanced previously, with basic criteria being vegetative.

This genus is restricted to the savannas of the upper Rio Negro and upper Orinoco drainages. Although it was described in 1828, it has hitherto been known by only five collections, with three described species. Additional recent collections by Schultes and ourselves have both clarified and confused the species. Upon examination of single branches, the most striking floral character is the connective development differences in the two whorls of stamens. However, while the dimorphic or essentially monomorphic character of the stamens seems relatively constant for single sprigs, examination of entire collections reveals quite a disturbing floral variability in the sprigs assigned to a single collection number, despite vegetative constancy in the collection. The heterostemonous feature is especially evident in the Schultes collections from the Rio Vaupes drainage. Within the recent Venezuelan collections, the stamen variability exists, although less striking fashion. One other disturbing phenomenon is the presence or absence of glandular hairs on style and/or filaments of some collections both Colombian and Venezuelan. Since both P coriaccum and P hiiberioides are spare shrubs, a collection number includes branches from several plants, at least in the Venezuelan collections.

I am indebted to the United States National Herbarium for the opportunity to examine all the specimens for each Schultes & Cabrera collection number. The herbaria at Munich and Paris have permitted the study of the holotypes of P coriaceum and P. huhcrioides. Drs Baehni and Weibel of Geneva kindly supplied information from the de Candolle herbarium and on the relations between Martius and de Candolle.