Boyania ayangannae Wurdack
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Authority
Maguire, Bassett & Wurdack, John J. 1964. The botany of the Guayana Highland--Part V. Mem. New York Bot. Gard. 10: 1-278.
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Family
Melastomataceae
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Scientific Name
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Description
Latin Diagnosis - Herba suffruticosa simplicicaulis vel vix ramosa 15-50 cm alta; caulis primum dense glandulis sessilibus vel vix stipitatis rubris obsitus tarde glabratus. Petioli 1-1.5 cm longi lateraliter dense setulosi pilis laxis 0.5-1 mm longis, nodis interpetiolaribus membrana elliptica ca. 2 mm alta stipuliformi caduca instructis; lamina 5-12 X 3-6 cm late ovato-elliptica apice late acuta basi obtusa vel rotundata membranacea, supra sparsissime vel modice strigulosa pilis laxis 0.5-1 mm longis, subtus in superficie sparse et in venis modice cum glandulis sessilibus clavatis obsita in venis primariis sparse glanduloso-setulosa alioqui glabra, 5-nervata jugo marginali tenuiore venulis laxe reticulatis, ad margines inconspicue undulato-serrulata et distanter ciliolata dentibus ca. 2-2.5 mm inter se distantibus. Inflorescentia 2-3 cm pedunculata, pedunculo glabro circum medium bibracteato bracteis 4-9 mm longis strigulosis trinervatis; ramuli plerumque 4 verticillati divaricati 3-5 cm longi glabri floribus 3-5 secundis; bracteolae ca. 2 x 1 mm elliptico-obovatae glabrae ad margines vix erosae ad pedicelli basim insertae; pedicelli 3-5 mm longi basim versus glabri ad apicem sparse laxo-setulosi. Hypanthium (ad torum) 2.1-2.5 X 2.3-2.4 mm dense vel modice pilis fragilibus laxis glanduliferis basi incrassatis ad 1.5 mm longis obsitum vix 10-costatum; calycis tubus 0.4-0.5 mm altus, lobis obverse ellipticis apice rotundatis et 0.1 mm unimucronulatis extus tuboque dense pilis laxis fragilibus plerumque non glandulosis interdum apicem versus paucibarbellatis 1.5-3.5 mm longis ornatis. Filamenta 2.5-3 mm longa glabra; antherarum thecae 3.4-4 mm longae subulatae minute uniporosae, appendice dorsali 0.8-1.2 mm longa, appendice ventrali 0.8-1 X 0.2-0.4 mm distaliter vix expansa et emarginato-truncata vel trilobulata. Stylus 8-9 X 0.25 mm glaber; stigma truncatum; ovarium apice in collum 0.8 mm altum marginaliter dense brevissimeque glanduloso-setulosum circum stylum protractum. Fructus ignotus.
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Discussion
Fig. 67, a-f.
Type. Herb, leaves medium green above and whitish green beneath, calyx red, corolla white, infrequent on rotting logs in talus forest along northeast side of Mt. Ayanganna, upper Mazaruni River basin, Pakaraima Mts., British Guiana, alt. 800-900 m, 16 Aug 1960, Stephen S. Tillett, Carolyn L. Tillett, & Rufas Boxjan 45152 (holotype US 2343864). Paratypes. BRITISH GUIANA, Pakaraima Mts. Mt. Ayanganna: talus forest slopes on northeast side, alt. 800-915 m, Tillett, Tillett, & Boyan 45000, 45151. Membaru-Kurupung Trail: rocks in gorge, alt. 1000 m, Maguire & Fanshawe 32105.
All of the previously described genera and species of Bertolonieae have, as far as is known, 2-4-celled ovaries. Boyania would key otherwise to Diplarpea (with long calyx lobes and oblong anthers with a short blunt dorsal calcar) or to Monolena (with glabrous hypanthia and connectives merely tuberculate dorsally). Probably Boyania will serve to emphasize the union of the New World Bertolonieae with the Old World Sonerileae; the intertribal hybrids of horticultural literature have tainted the traditional division between the tribes, although I have never seen such hybrids from accurately-named parents. None of the 5-merous Old World genera treated by Cogniaux and subsequent taxonomists seems to have the floral character combination seen in Boyania of completely superior ovary without hypanthial septs and subulate anthers with large dorsal and ventral appendages. Although the fruit of Boyania is unknown, the general generic relationship seems quite certain because of the habitat and pubescence similarities. Of the Tibouchineae, only Ernestia, with bilobed ventral connective appendage, 3-4-celled ovary, and quite different pubescence, would at all conform as a possible relative. Boyania commemorates the extensive field work performed by Jonah and Rufas Boyan for the British Guiana Forestry Department and The New York Botanical Garden through many years. Two of the three sheets of Tillett et al. 45000 show nearly glabrous upper leaf surfaces, while all other specimens (including the type number) have moderately pubescent upper blade surfaces; more collections are needed to evaluate this feature.