A taxonomic revision of the genus Gouania Jacq. (Rhamnaceae) is presented for Madagascar and the other western Indian Ocean islands. Seventeen species are recognized, of which nine are described and published as new (all endemic to Madagascar): G. ambrensis Buerki, Phillipson & Callm., G. callmanderi Buerki, G. cupreifolia Buerki, Phillipson & Callm., G. cupuliflora Buerki, Phillipson & Callm., G. gautieri Buerki, Phillipson & Callm., G. perrieri Buerki, Phillipson & Callm., G. phillipsonii Buerki, G. taolagnarensis Buerki, Phillipson & Callm., and G. zebrifolia Buerki, Phillipson & Callm. Sixteen species occur in Madagascar, of which 13 are endemic and three are common to Madagascar and one or more of the smaller Indian Ocean islands. The latter include G. laxiflora Tul., a species which is also present on mainland Africa. One species, G. mauritiana Lam., is endemic to Réunion Island. We recognize two subspecies within G. scandens (Gaertn.) R. B. Drumm.: G. scandens subsp. scandens and G. scandens subsp. glandulosa (Boivin ex Tul.) Buerki, Phillipson & Callm., the latter transferred from G. glandulosa Boivin ex Tul. Past confusion about the identity of this species is discussed. Five names are lectotypified: G. aphrodes Tul., G. glandulosa [= G. scandens subsp. glandulosa], G. laxiflora, G. lineata Tul., and G. tiliifolia Lam. Both lectotype and epitype are designated for G. mauritiana. Conservation assessments are provided for all species within their primary areas of occurrence.

A majority of angiosperm species of vines and lianas use their stem apices for twining and adherence to support structures. Prior observations have suggested a strong predominance of twining orientation in a dextral (right-handed) direction. We present here the chirality of twining (handedness) for 60 taxa representing 21 families encountered in a terra firme Amazonian forest community in Peru. We surveyed 145 stems of climbers that represented one to eight individuals of a given taxon. We demonstrate that dextral chirality is phylogenetically widespread among angiosperm stem climbers and suggest that phylogenetic deviations from the dextral pattern represent independent evolutionary events. Phylogenetic constraint might be invoked to explain the dextral dominance among climbers, but dextral circumnutation is not ubiquitous in other angiosperm organs. Here we also clearly define climbing chirality because of the confusion in previous literature, and we compile published family-level reports of deviations from dextral orientation. This study underscores the need for approaching the twining chirality of plants from genetic, developmental, and physiologic perspectives to clarify the basis for the preferred twining orientation among angiosperm climbers.

The circumscription of genera within the family Rubiaceae is by no means a precise endeavor at the current time. For example, the genus Relbunium (Endl.) Hook. f. is currently included as a section of Galium L., sensu Dempster, although this placement does not have unanimous support among specialists. To clarify these uncertainties, this study examined whether Relbunium is an autonomous genus or a section of Galium by analyzing the morphology and development of flowers and fruits of the following species: G. latoramosum Clos, G. uruguayense Bacigalupo, R. equisetoides (Cham. & Schltdl.) Ehrend., R. gracillimum Ehrend., R. hirtum (Lam.) K. Schum., R. humile (Cham. & Schltdl.) K. Schum., R. humilioides M. L. Porto & Ehrend., R. hypocarpium (L.) Hemsl., R. longipedunculatum Mariath & Ehrend., R. mazocarpum Greenm., R. megapotamicum (Spreng.) Ehrend., R. nigro-ramosum Ehrend., R. ostenianum Standl., R. richardianum (Gillies ex Hook. & Arn.) Hicken, and R. valantioides (Cham. & Schltdl.) K. Schum. This morphological data set and analysis were then used to construct a cladogram, which indicates that Galium is a sister group to Relbunium and further characterizes Relbunium as a monophyletic clade that should be considered an autonomous genus.

The present treatment includes the first revision of 31 species of Axonopus P. Beauv. (Poaceae) in Argentina, southern Brazil, Bolivia, continental Chile, Paraguay, and Uruguay. A key to the species is provided, together with detailed descriptions, illustrations, distribution ranges, and a discussion of the morphological relationships of the species. Axonopus caulescens (Mez) Henrard is first reported for Bolivia, and the names A. eminens (Nees) G. A. Black and A. kleinii L. B. Sm. & Wassh. are synonymized with A. siccus (Nees) Kuhlm. and A. uninodis (Hack.) G. A. Black, respectively. The names Panicum hagenbeckianum Kuntze and Paspalum ulei Hack. are lectotypified.

The African Plants Initiative (API) was conceived as a web-based, electronic venture that would provide rapid access to images of type specimens of African plant names. This soon grew to also encompass images of living plants, associated taxonomic literature, artwork, and related texts. In many respects, Africa, which is host to a flora of over 50,000 species, for which about six times that number of alternative and incorrect names are available, has historically lagged behind the world in terms of both taxonomic capacity and access to the global electronic ether. Through the API, a consortium of 73 institutions from the North and South, 291,289 specimen images alone are now available for accessing through the Internet. In this regard, the API has been a pioneer in and has become a catalyst for facilitating the generation and dissemination of fundamental taxonomic information on African plants, a role it is increasingly fulfilling through the JSTOR Plant Science portals.

Leitneria floridana Chapm., a shrub indigenous to North America, was long considered to be the sole member of the family Leitneriaceae, with uncertain affinities in and outside the class Amentiferae. Recent molecular analyses, however, show that the species is closely related to the genera Brucea J. F. Mill., Soulamea Lam., and Amaroria A. Gray in the family Simaroubaceae. Here, I report embryological features of L. floridana and provide anatomical corroboration for the molecular simaroubacean affinities of this species. I compared its embryology with those of the families Simaroubaceae, Meliaceae, and Rutaceae, which form a monophyletic clade in the order Sapindales. Comparisons showed that although Leitneria Chapm. resembled all three families embryologically, it fits best within the Simaroubaceae through possession of an unspecialized chalaza, straight and exarillate seeds, a non-multiplicative testa, a non-crystalliferous endotesta, and absence of a fibrous exotegmen. Within the Simaroubaceae, Leitneria also shares with Brucea the synapomorphies of a micropyle formed by an elongate, irregularly folded inner integument and a persistent tegmen composed only of endotegmen. Members of the Simaroubaceae are still poorly known embryologically, but available evidence supports the close affinity of Leitneria and Brucea.