The six species of Fockea Endl. (Apocynaceae, Asclepiadoideae, Fockeeae) occur in Africa south of the equator from southern Kenya to South Africa. A phylogeny for all six species of Fockea is inferred from data obtained from two chloroplast markers (the trnL-F region and the psbA-trnH intergenic spacer), one nuclear marker (ITS1 region), and morphology. Fockea is found to be monophyletic and sister to the bitypic Cibirhiza Bruyns. Morphologically, Fockea is characterized by the deeply tubular outer corona that is filled by the erect, inflated sterile appendages of the anthers. Of the six species, the widely distributed but exclusively tropical Fockea multiflora K. Schum. is sister to the other five members of Fockea, and, among these five, the widely distributed and mainly tropical F. angustifolia K. Schum. is sister to the remaining four, which are endemic to southern Africa. It is shown that Fockea most probably originated in South Tropical Africa. A complete taxonomic account is provided for the six species of Fockea, and their known distribution is mapped. Lectotypes are designated for Fockea capensis Endl., F. monroi S. Moore, F. schinzii N. E. Br., F. sessiliflora Schltr., and F. sinuata (E. Mey.) Druce. Neotypes are designated for Brachystelma macrorrhizum E. Mey., Fockea angustifolia, and F. comaru (E. Mey.) N. E. Br. An isotype has been located for F. multiflora.

In order to test the monophyly of Mandevilla Lindl., the largest genus in tribe Mesechiteae (Apocynaceae, Apocynoideae), and its affinities to other genera in the tribe, maximum parsimony analysis was conducted on a data set comprising DNA sequences from five plastid loci (rpl16, rps16, and trnK introns; trnS^GCU-trnG^UUC intergenic spacer; and matK gene), as well as morphological data for 65 taxa of Mesechiteae (48, Mandevilla) and nine taxa from other tribes of the subfamily. Mandevilla, as circumscribed by Pichon, was found to be monophyletic, whereas Woodson's circumscription proved to be polyphyletic. Thus defined, Mandevilla forms a strongly supported clade that can be divided into six clades of species groups. Most of the infrageneric taxa of Mandevilla proposed by Woodson and Pichon are polyphyletic. Many of the diagnostic characters previously used to define taxonomic groups are shown to have arisen multiple times, rendering them unsuitable for classificatory purposes. The similar growth form and tubular flowers of Macrosiphonia Müll. Arg. and Telosiphonia (Woodson) Henr., two geographically disjunct segregates, represent the most extreme case of parallel evolution within Mandevilla, with their striking similarities most likely correlated to colonization of open, dry habitats and pollination by hawkmoths.

The taxonomic revision of species of the genus Axonopus P. Beauv. series Suffulti G. A. Black is presented. This series includes perennial species, frequently growing in savannas and in grasslands, on argillaceous or sandy ground with rocky outcrops, at altitudes up to 3500 m. The plants are rhizomatous or stoloniferous, with conduplicate sheaths and narrowly linear to linear-lanceolate blades, flat to folded along their entire length, or open toward the apex. The inflorescences are exserted from the apex of the culms; they consist of spiciform racemes of variable number, mainly digitate. The rachis of each raceme is triquetrous, sinuous, with hispidulous angles, sometimes with long and rigid hairs. The upper lemma and the upper palea are indurate, dark brown, papillose, and shiny. Sixteen species are here considered within Axonopus series Suffulti, principally distributed in South America, with A. ciliatifolius Swallen and A. jeanyae Davidse endemic species of Belize and Panama, respectively. Description of morphological characters and microcharacters of the upper floret, a key to identify the species, descriptions, synonymy, geographical distribution, and illustrations of characters of taxonomic value are given. Finally, lectotypification of series Suffulti is established, and A. ramboi G. A. Black is included in A. argentinus Parodi as a synonym.

Chromosome counts and karyotype information from 41 populations of 20 species and 6 varieties of Nicotianeae (Solanaceae) from South America belonging to Bouchetia Dunal (x  =  8), Fabiana Ruiz & Pav. (x  =  9), Leptoglossis Benth. (x  =  10), Nierembergia Ruiz & Pav. (x  =  8, 9), and Petunia Juss. (x  =  7, 9) are given, including first reports from 14 taxa: F. densa Rémy, N. ericoides Miers, and P. patagonica (Speg.) Millán, with 2n  =  2x  =  18, and N. browallioides Griseb., N. calycina Hook., N. graveolens A. St.-Hil., N. linariifolia Graham var. glabriuscula (Dunal) A. A. Cocucci & Hunz., var. pampeana (Millán) A. A. Cocucci & Hunz., and var. pinifolioides (Millán) A. A. Cocucci & Hunz., N. pulchella Miers var. pulchella and var. macrocalyx (Millán) A. A. Cocucci & Hunz., N. rivularis Miers, N. tucumanensis Millán, and N. veitchii Hook., with 2n  =  2x  =  16. All species studied are diploids, and most have 2n  =  16. In addition, infraspecific polyploidy is recorded for the first time in N. rigida Miers (2n  =  4x  =  32) and confirmed in N. aristata D. Don (n  =  3x  =  24, 2n  =  6x  =  48). In general, karyotypes of the examined species are symmetrical and composed of comparatively small and uniformly sized chromosomes, mostly of the metacentric (m) type except in L. linifolia (Miers) Griseb., P. axillaris (Lam.) Britton, Stern & Poggenb., and P. patagonica, where submetacentric (sm) chromosomes are predominant. There are one or, rarely, two chromosomes bearing nucleolar organizing regions per basic complement. In Nierembergia, karyotype data reflect species grouping. Results suggest that Bouchetia is the closest taxon to Nierembergia, while Leptoglossis, Petunia, and Fabiana appear more distant. Possible chromosome number evolution in the tribe is speculated based on molecular phylogenetic studies by other authors. In Nierembergia, x  =  9 is proposed to be derived from x  =  8. Dysploid changes in chromosome number and conservation of chromosome morphology in the karyotypes appear as important evolutionary events in the tribe, while polyploidy is noteworthy only in Nicotiana L.

Chromosome numbers and observations on meiotic chromosome behavior of 37 taxa of American Panicoideae are given. The taxa studied are: Axonopus scoparius (Flüggé) Kuhlm., Cenchrus myosuroides Kunth, Dichanthelium aciculare var. aciculare (Desv. ex Poir.) Gould & C. A. Clark, D. acuminatum var. acuminatum (Sw.) Gould & C. A. Clark, Echinochloa chacoensis P. W. Michael ex Renvoize, Eriochloa montevidensis Griseb., Isachne arundinacea (Sw.) Griseb., Panicum hirticaule J. Presl, P. stoloniferum Poir., P. trichanthum Nees, Paspalum blodgettii Chapm., P. buchtienii Hack., P. caespitosum Flüggé, P. candidum (Humb. & Bonpl. ex Flüggé) Kunth, P. ceresia (Kuntze) Chase, P. clavuliferum C. Wright, P. commune Lillo, P. denticulatum Trin., P. ekmanianum Henrard, P. ellipticum Döll, P. fimbriatum Kunth, P. glabrinode (Hack.) Morrone & Zuloaga, P. glaucescens Hack., P. hartwegianum E. Fourn., P. inconstans Chase, P. indecorum Mez, P. juergensii Hack., P. pauciciliatum (Parodi) Herter, P. penicillatum Hook. f., P. plicatulum Michx., P. prostratum Scribn. & Merr., P. saccharoides Nees ex Trin., P. squamulatum E. Fourn., P. variabile (E. Fourn.) Nash, P. wrightii Hitchc. & Chase, Urochloa fusca (Sw.) B. F. Hansen & Wunderlin, and U. lorentziana (Mez) Morrone & Zuloaga. Nine counts are first reports for Echinochloa chacoensis (2n  =  ca. 72), Panicum stoloniferum (2n  =  20), Paspalum buchtienii (2n  =  20), P. ceresia (2n  =  40), P. ekmanianum (2n  =  20), P. glabrinode (2n  =  20), P. inconstans (2n  =  ca. 60), P. penicillatum (2n  =  40), and P. variabile (2n  =  40). Ten counts differed from previously published counts: Axonopus scoparius (2n  =  60), Cenchrus myosuroides (2n  =  ca. 72), Isachne arundinacea (2n  =  20), Paspalum denticulatum (2n  =  20), P. ellipticum (2n  =  40), P. fimbriatum (2n  =  ca. 40), P. hartwegianum (2n  =  40), P. saccharoides