A revision of Pterolepis (Melastomataceae: Melastomeae)

Pterolepis consists of herbs and small shrubs with pink, purple, or white (3-)4–5-merous flowers, stamens with basal-ventrally prolonged connectives, and cochleate seeds. The majority of the species occur in central Brazilian cerrado vegetation, but two weedy species have become widespread, one ranging from Bolivia to southern Mexico, the other from Paraguay to the West Indies. Pterolepis appears related to the paleotropical genera Osbeckia, Melastoma , and Dissotis and to the neotropical genus Tibouchina . The main diagnostic feature of the genus are branched emergences in the intercalycine sinuses but these are variable among the species and also occur in many paleotropical and two neotropical species, casting some doubt on their taxonomic value above the species level. Within Pterolepis , 14 of the 80 taxa proposed by previous authors are recognized and eight species are illustrated; one new species, P. picorondonica from Amazonian Brazil, and a new variety, P. parnassiifolia var. piatensis from Bahia, are described. Also provided are scanning electron micrographs of the seeds of most, and distribution maps of all species.     

Taxonomic revision of Driessenia (Melastomataceae)

The genus Driessenia Korth. comprises fourteen species and two varieties. Eleven species are endemic to Borneo, the remaining three species occur on Sumatra, Java or Sulawesi. Five species ( D. sessiliflora, D. planopetiolata, D. attenuata, D. grandithyrsa and D. aequiappendiculata ), one variety ( D. microthrix Stapf var. pteroclada ) and one combination ( D. dispar (Cogn.)) are new. The genus Triuranthera Back. is made a synonym of Driessenia . The revision includes a key to the species, illustrations of various floral parts and maps of distribution.     

A new Mecranium (Melastomataceae) from Hispaniola

Mecranium revolutum is described from the Massif de la Hotte of Haiti and compared with three similar species that are also endemic to this interesting region. The lower elevation (1000–1600 m) forests of Parc National Pic Macaya are discussed briefly.     

A new epiphytic blakea (Melastomataceae) from Panama

Blakea wilburiana is described from the low volcanic uplift of El Valle de Anton in central Panama. Hirsute pubescence, papery leaves, and large, thin floral bracts suggest a marked affinity withB. bracteata Gleason of South America. A character tabulation, comparing the two species, is included together with illustrations of the diagnostic morphological features.     

A new species of Microlicia (Melastomataceae) from Brazil

A new species of the genusMicrolicia,M. flava, from the highland “campo rupestre” vegetation of Serra da Canastra National Park, São Roque de Minas, Minas Gerais, Brazil, is described and illustrated.     

A new species of Memecylon (Melastomataceae) from India

Memecylon sivadasanii , a new species of Melastomataceae from India is described and illustrated. The new species is allied to M. angustifolium and M. rivulare.     

A revision of Sullivantia (Saxifragaceae)

Sullivantia (Saxifragaceae) is restricted to the United States; its species occur in very specialized habitats such as wet cliffs and moist canyon walls in scattered localities from Washington and Oregon, eastward to Wyoming, Montana, Colorado, Missouri, Iowa, Illinois, Minnesota, Wisconsin, Indiana, Ohio, and Virginia. Relationships in the genus were reevaluated using data from morphology (including the use of greenhouse-grown plants), crossability, and flavonoid chemistry. The conclusion of this study is thatSullivantia comprises four morphologically similar allopatric taxa:S. oregana, S. hapemanii var.hapemanii, S. hapemannii var.purpusii, andS. sullivantii.     

A revision of Cycniopsis (Scrophulariaceae)

The genus Cycniopsis is reexamined. Generic and specific delimitation is discussed with respect to morphological characters, including seed structures studied by scanning electron microscopy. A hierarchical key to Cycniopsis and related genera is presented.
Two species are recognised, C. humifusa and C. humilis comb. nov. Several names are reduced to synonymy, and three lectotypes and one neotype are selected. Both species are illustrated, and a distribution map is provided.     

A revision of Schimperella (Brachytheciaceae)

Schimperella is a small African genus related toRhynchostegium. It is characterized by noncomplanate plants with erect capsules and reduced endostomes. Two species are recognized:S. katalensis andS. rhynchostegioides. A proposed synonym ofS. rhynchostegioides, Rhynchostegium nervosum, is best placed inIsothecium, asIsothecium nervosum.     

A third species of Tessmannianthus (Melastomataceae: Merianieae) from Panama

Tessmannianthus cereifolius, a new species from eastern Panama, is described, illustrated, and compared to its closest presumed relative,T. heterostemon of Ecuador and Peru. The new species is distinguished by its truncate calyx, absence of exterior calyx teeth, and complete glabrosity. A 5-celled ovary is reported for the first time inT. cereifolius andT. heterostemon. The latter was previously thought to be characterized by a trilocular ovary. A distribution map and a revised key to the three Panamanian species ofTessmannianthus are also provided.     

A synoptical revision of Blepharidachne (Poaceae)

Blepharidachne is a disjunct American genus with four species:B. kingii (S. Wats.) Hackel (Great Basin of western U.S.A.) andB. bigelovii (S. Wats.) Hackel (Coahuila, Mexico and Texas, U.S.A.) in North America;B. benthamiana (Hackel) A. S. Hitchc. andB. hitchcockii Lahitte, both in central and western Argentina.Blepharidachne kingii is the only species with perfect flowers, the other three being monoecious as a result of a series of reductive processes. After a discussion of these morphological peculiarities, heretofore overlooked, the article is completed with a brief taxonomic synopsis of the genus.     

A new revision of Joosia (Rubiaceae-Cinchoneae)

Joosia comprises 11 species, three of which are here described as new: J. longisepala, J. multiflora, and J. obtusa. Joosia pulcherrima Steere is resurrected from synonymy. Joosia is a close relative of Cinchona, Ladenbergia, and Remijia, from all of which it differs in having wilting rather than caducous stipules, an inflorescence of predominantly monochasial cymes, and corolla lobes with marginal showy appendages. It occurs from western Panama along the Andes south to northern Bolivia, with a pronounced center of diversity in Ecuador. On the basis of a cladistic and biogeographical analysis, it is hypothesized that the genus originated in the lowland forest of the westernmost Amazon Basin.