The identity of Aloe steudneri Schweinfurth (Asphodelaceae) is discussed. It is shown that the two specimens quoted in the protologue as syntypes of that species are not conspecific and that only one, Steudner 448 from the Semien Mountains of Ethiopia, is still in existence. This specimen is consequently the lectotype of A. steudneri. The plants growing on Mt. Saber, in Eritrea and considered by Schweinfurth and subsequent workers to belong to A. steudneri, represent a distinct taxon, described here as Aloe neosteudneri.

Aloe argyrostachys, a remarkable new species described in this paper, is related to A. compressa H. Perrier (s.l.) from which it differs, inter alia, by its caulescent habit and larger size and by its white perianths, with segments not recurved, held in a dense, conical raceme. The species was found in the wide expanse of quartzite mountains that constitute much of the country west of Antsirabe, in the central highlands of Madagascar.

The taxonomy of the genusConophytum has been problematic since its inception. The geographical isolation of the many populations, confined to the summits of small hills or isolated stony vlaktes, has ensured an enormous variation and an explosion of forms. Up to now, all published taxonomic keys have been limited to small groups of species or subspecies; no taxonomic key has been compiled for the entire genus. In the present paper, a key to the entire genus Conophytum is proposed. Even though traditional statistical methods would serve well for this task, they were not used. Instead key phrases are proposed based on subjective knowledge of the genus.

Aloe polyphylla and A. calcairophila are two endangered species that are endemic to South Africa and Madagascar respectively. Generally ex situ conservation through in vitro culture involves growing plant material in nutrient rich media containing plant growth regulators to achieve shoot multiplication and rooting. In this study we report shoot multiplication and rooting of these two important plants in culture using half strength Murashige and Skoog (MS) medium containing glucose as the carbon source. Plants developed in glucose-containing medium were of superior quality in both species compared to those grown on standard carbon source, sucrose. This method has been applied to micro-propagate other species of Aloe at the Royal Botanic Gardens, Kew, England.

While total cactus diversity of Uruguay is significantly less than that of the surrounding countries, Uruguay is none the less part of the diversity centre of the Notocactus group of the genus Parodia. Parodia allosiphon is a relatively recently described taxon with a limited distribution in the frontier region of Dept. Rivera (Uruguay) and neighbouring Rio Grande do Sul (Brazil). A recent collection made in Dept. Artigas (Uruguay) significantly extends the distribution range of the taxon. Its conservation status is evaluated as “near-threatened”.

The genus Haageocereus (Cactaceae) is almost endemic to Peru, occupying arid areas of river valleys draining westwards off the Andes. Extensive fieldwork, morphological studies, literature revision and a study of the types led to the delimitation of 9 species and 6 heterotypic subspecies. Nomenclatural innovations include H. acranthus subsp. backebergii N. Calderón subsp. nov., H. versicolor subsp. pseudoversicolor (Rauh & Backeb.) N. Calderón comb. nov. and the recognition of H. repens Rauh & Backeb. Descriptions and keys are accompanied by line drawings and plates including SEM photos of the seeds for almost every taxon. Exsiccata prepared during this study constitute approximately 80% of existing Haageocereus herbarium samples from wild origin. Conservation assessments based on the IUCN Red List categories (2001) determined 3 taxa as Critically Endangered (CR), 8 taxa as Endangered (EN) and 5 taxa as Vulnerable (VU) in Peru.

The only known illustration contemporary with the protologue of Echinocactus mammulosus Lem. (1838) and the designated neotype of the basionym of Parodia mammulosa (Lem.) N.P. Taylor, is discussed and reproduced.

Brazil is the third major centre of diversity for the family Cactaceae, with approximately ¾ of the species found in the country being endemic, and a total of 162 native species, including around 20 belonging to Pilosocereus. This family is exclusively pollinated by animals, varying widely between beetles, bees, butterflies, moths, hummingbirds and bats. Pilosocereus tuberculatus is a tree-like cactus with candelabriform branching, with a relict distribution restricted to a few localities in the states of Pernambuco, Bahia, Sergipe and probably southern Piauí. The present work reports observations of bat-pollination in natural populations of the species in an area of dryland woody vegetation (‘caatinga’) in the municipality of Buíque, state of Pernambuco, Brazil. The slightly zygomorphic flowers have olive-green outer perianth-segments and white inner perianth-segments with purplish spots, and a straight, almost cylindric flower tube 3.5–4.0 cm long. Nocturnal anthesis, a strong smell and internally white flowers with abundant nectar (23–309µl) of relatively low sugar content (9.5–17.0%) are characteristic of the bat-pollination syndrome. Pollen is available and the stigma is functional during anthesis as a whole, from between 18:00–18:20h and 8:20–8:50h the following morning. Visits were recorded during the day by bees (Apis mellifera, Trigona spinipes and Xylocopa grisescens) and a hummingbird(Heliomaster squamosus) and during the night by bats (Glossophaga soricina and Lonchophylla mordax). The bats were observed at intervals varying between 5 seconds and 55 minutes, during 18 nights (i.e. 270 hours of observation). In P. tuberculatus spontaneous self-pollination did not produce fruits. The ratio of fruits formed by cross-pollination (69%) compared with manual self-pollination (0%) indicates that the predominant reproductive system in P. tuberculatus is allogamy, and that its reproduction depends on the efficiency of the pollen-vectors. Based on behaviour displayed during bat, bee and hummingbird visits, and the ratio of natural fruit formation, P. tuberculatus depends mostly on its nocturnal visitors for pollination. Bat-pollination, which is predominant for the genus Pilosocereus, has been interpreted as a mechanism of parallel evolution between cacti and bats, and it is possible to consider P. tuberculatus as an example of this close relationship, including a the new record of the glossophagine bat L. mordax as a cactophilic bat.

Based on more than 1,000 collections of Drosanthemum and studies of all 131 type sheets and drawings, a new subdivision into eight subgenera is offered for the genus, using mainly fruit and flower types to recognize the separate units. In this way, a base is laid for a more in-depth study of the genus of c. 130 recognized species. The new subgenera are D. subg. Drosanthemum, D. subg. Lutea H.E.K. Hartmann, D. subg. Necopina H.E.K.Hartmann, D. subg. Ossicula H.E.K.Hartmann, D. subg. Quastea H.E.K.Hartmann, D. subg. Speciosa H.E.K.Hartmann, D. subg. Vespertina H.E.K. Hartmann, and D. subg. Xamera H.E.K. Hartmann. For the first time, the distribution maps are created with the new program Taxo2Map from an ACCESS databank.

In SEM investigations of various members of the family Aizoaceae, it was possible to demonstrate the presence of nectar slits over nectar glands in strict correlation; nectaries are therefore mesophyllous, glands lack any intercellular spaces, and exudation of nectar occurs through the slits. Based on these results, a revised classification of nectaries for Aizoaceae is offered, and the presence of nectaries in the genus Glottiphyllum can be shown.

Within the cactus genusMammillaria, the circumscription of series Stylothelae has been controversial. This has resulted in circumscriptions that group species into a single series with various species groups (M. crinita Group, M. bombycina Group, M. glassii Group, and M. mercadensis Group) and circumscriptions that split the series into a number of subsequent series. Utilizing PCR sequencing methods, the authors investigated phylogenetic relationships in the Stylothelae and discovered the deletion of the entire rpl16 intron of the chloroplast in a number of members of the series. To date, this deletion has not been documented elsewhere in the Cactaceae. Specifically, the deletion of the rpl16 intron in the Stylothelae is restricted to those species that have either been treated as a distinct species group (M. crinita Group) within the series, or as a unique series in their own right (series Stylothelae sensu stricto).

Agave americana L. var. americana and A. sisalana Perrine are here listed and described as exotic alien plants that have become naturalised in the Cape Floristic Region of South Africa. A key is provided to assist with the identification of the two species.