The goal of this paper is to rehabilitate the genus Monvillea, based on Cereus cavendishii as the type species, which identity has been attributed to another genus. The name Cereus cavendishii Monville corresponds to a species of northern Argentina, Paraguay, eastern Bolivia and southern Brazil, as had been considered traditionally in the literature, and that species was typified accordingly by Heath in 1992. As a consequence, Monvillea keeps its nomenclatural validity. Additionally, an epitype is here designated. The inclusion or not of all or some of the species in Monvillea under Cereus is a taxonomic matter, and hence a matter of opinion, but the pertinence of Cereus cavendishii to Monvillea sensu Britton and Rose cannot reasonably be disputed.

In an older paper, Reznik (1957) studied flower pigments from 37 Conophytum samples and found three main pigments: one betaxanthin (in samples with yellow flowers) and two betacyanins (betanin 1 in samples with purple flowers and betanin 2 in one sample with rose-purple flowers), as well as 6 flavonols as co-pigments. Here, the results from Reznik (1957) and related older studies are compared with more recent morphological-phylogenetic studies (Opel 2005b) with regard to the agreement or deviation with respect to subdivisions of the genus Conophytum. The mutually exclusive distribution of two flavonols in Conophytum is phylogenetically informative: flavonol 1 is restricted to the basally diverging lineages of the Biloba Grade (including Conophytum taylorianum), and flavonol 2 was found in the group containing the remainder of Conophytum, probably indicating monophyly. In conjunction with phylogenetic data of Opel (2005b), floral pigment data suggest that Conophytum sect. Biloba could be provisionally recognized as a possibly paraphyletic assemblage comprising all members of the Biloba Grade including C. taylorianum but excluding C. herreanthus, and that sect. Herreanthus should encompass C. herreanthus only.

The Eastern Cape is extremely diverse and is a climatic, topographic and geological transition zone. This transitional nature of the environment is reflected in the phytogeographical and phytosociological complexity of the Eastern Cape. The region has a very diverse flora comprising ca. 8 300 taxa (species and infraspecific taxa). A total of 39 aloes occur in the Eastern Cape of which ten (26%) are endemic to the area, with a further four (10%) being near-endemic. A key to the aloes of the Eastern Cape is provided, as well as a short description, distribution map and information on habitat, flowering time, and conservation status for each of the species.

Plants of the genus Schlumbergera are popular houseplants cultivated throughout the world. While most species in the genus, including the cultivars of Schlumbergera truncata, have been found to be self-incompatible, one cultivar, S. truncata ‘Thor Olga’, is shown here to produce fruit containing viable seeds through self pollination. Three of seven flowers (~43%) set fruit, including two fruits from which viable seeds were collected. A total of 35 seeds from these two fruits were sown, of which nine germinated (~26% viability). The phylloclade shape for all nine progeny plants appeared similar to the S. × buckleyi type for the first year, with gently scalloped rounded edges and no teeth. After the first year, the phylloclade shape began to differentiate, with some remaining similar to the S. × buckleyi shape and others developing the typical S. truncata shape. One of the progeny resulting from the self fertilization was brought to flower, and, in addition to differing in flower color from the parent plant, the progeny plant is very dissimilar to its parent in its branching architecture and its arching pendulous habit, as well as in the size and shape of the phylloclades. The breakdown in self-incompatibility is thought to be associated with delayed pollination, since fresh mature pollen was placed on over-mature stigmas. This appears to be the first time successful self-fertilization of Schlumbergera truncata has been reported in the literature. It is reasonable to predict that other Schlumbergera cultivars/hybrids may likewise exhibit some degree of self-compatibility. The fact that the self-incompatibility mechanisms can be broken down, may lead to the development of a new range of cultivars with unique traits.

Stem epidermis of eight Pterocactus species was examined under light microscopy (LM) and scanning electron microscopy (SEM). The stomata belong to the paracytic type, with two to five subsidiary cells. The size of stomata and papillae and the density of both were measured and counted under LM. Under SEM the micromorphology of papillae was studied. These characters were used to distinguish anatomically the species of Pterocactus.

Las epidermis de los tallos de 8 especies de Pterocactus fueron examinadas con microscopio óptico (MO) y Microscopio Electrónico de Barrido (MEB). Los estomas corresponden al tipo paracítico, con dos a cinco células subsidiarias. El tamaño de los estomas y de las papilas, como así también la densidad de ambos fueron medidos y contados con el MO. La micromorfología de las papilas fue estudiada con MEB. Estos carácteres fueron usados para distinguir anatómicamente las especies de Pterocactus.

We studied the sole population of Opuntia fragilis in Illinois for four years, tracking plant and individual pad fates, and investigating flowering success. The population appears to be fairly stable in size from year to year. The fate of a given pad is strongly dependent upon the position of the pad within the plant; basal pads and transitional pads are likely to remain from year to year, while terminal pads experience substantially higher rates of death or fragmentation, and are much more likely to produce new growth and thus become transitional pads themselves. A fungal “black spot” disease, probably a result of winter damage, appears to negatively affect pad survival during some winters but not during other winters. While genetic diversity is not low, flowers do not produce viable seed, even when controlled cross-pollinations are performed, although they are visited by a variety of potential insect pollinators.

Fockea multiflora K. Schum. (Apocynaceae) was previously known from southern, southeastern and eastern Africa with a distributional gap between the Zambezi River valley and central Tanzania. Six localities in Malaŵi, that fall within this previous gap, are reported on here.

Setiechinopsis is a monotypic Argentine endemic genus (S. mirabilis) of the tribe Trichocereeae. It is one of the most difficult cacti to find and grows in lowlands and brackish soils. Our aim was to analyze for the first time its cytogenetic features in two populations. It presented 2n = 22 with small chromosomes (mean chromosome length = 2.87 μm; mean haploid genome length = 31.60 μm). The karyotype was symmetrical: 10m 1sm. The first m pair (No. 1) had nucleolar organizing regions and terminal microsatellites on the short arms. The ratio of the length of the largest m chromosome pair (No. 1) to that of the smallest m chromosome pair (No. 10) was 1.55. Banding patterns showed CMA /DAPI⁻ constitutive NOR-associated heterochromatin in m chromosome pair No. 1, comprising the distal satellite and a small proximal band. Additionally, four m chromosome pairs showed CMA /DAPI⁻ pericentromeric bands. The percentage of CMA /DAPI⁻ heterochromatin was 11.22% of the total karyotype length. No CMA⁻/DAPI bands were detected. The signal of the 18-5.8-26S gene was located in the satellite and the terminal portion of the short arm of pair No. 1. The signals of the 5S rDNA gene were located in pericentromeric regions in m chromosome pairs Nos. 2–5. The locations of the 18-5.8-26S sites coincided with the NOR-associated CMA /DAPI⁻ bands, whereas 5S sites coincided with the pericentromeric CMA /DAPI⁻ bands. Sizes, numbers, and intensities of both rDNA signals had a great similarity between the homologs. Comparisons with the few studies made in the Cactaceae suggest that morphological variation in the family was not followed by major modifications in karyotype formulae and chromosome size, but that the occurrence and distribution of different repetitive DNA fragments tend to vary among the different taxa so far analyzed.

Individuals of the cactus Cylindropuntia fulgida, are adapted to long periods of environmental stress with ephemeral periods of resource abundance (e.g., seasonal rains and subsequent nutrient mineralization) which requires this slow-growing cactus to act quickly to acquire nutrients. A short-term phenotypic response to varying levels of a fertilizer pulse was investigated in this species. Phenotypic plasticity could be a mechanism whereby this plant can modify its phenotype to allow for high resource intake during ephemeral nutrient pulses. The phenotype of a clone grown across fertilizer treatments was described for several morphological growth characteristics: root biomass, shoot length growth, weight increase, and number of new stem sprouts. Root concentrations of carbon (C) and nitrogen (N) were used to measure plasticity in nitrogen uptake capacity and allocation. Significant differences between clones were found in all response variables except root biomass, when each response variable was considered individually, but fertilizer treatment had an effect only on root nitrogen concentration and C:N ratio. However, when covariation among response variables was accounted for using principal components analysis, fertilizer treatment was shown to significantly impact root nitrogen allocation, above-ground growth and root biomass. In no case was a significant genotype-by-environment interaction found, indicating that there was not a diversity of responses among clones. These results demonstrate that this slow-growing species is able to respond to brief changes in the environment, which fact has important implications for the ecology and evolution of this species in a highly variable environment.