An obligatory cremnophyte, Delosperma expersum var. decumbens is transferred to the genus Drosanthemum and raised to species level. Drosanthemum decumbens grows on upper quartzitic sandstone cliff faces of the Table Mountain Group (Cape Supergroup) in the Ceres and Worcester region of the Western Cape, South Africa. It differs from Drosanthemum expersum by its re-sprouting lignotuber, procumbent to pendent stems, shorter pedicels 10–15 (–35) mm long, and fruiting capsules turning reddish before drying.

A solitary plant of the putative intercladal cross Echinopsis (Leucostele) atacamensis subsp. atacamensis × Echinopsis (Soehrensia) formosa was observed in the contact zone of the mostly allopatric populations of the parent species in the Salar de Atacama region in the Chilean Andes. The plant is intermediate between the parents in its characters. It was found to be sterile, despite normal-looking anthers (with abundant pollen) and stigma. In addition, an apparently typical individual of E. atacamensis with yellow flowers has been found, but it remains unknown whether this is merely a flower colour variant, or whether hybridization could be involved.

The island of Puerto Rico is home to five species of columnar, globular and semi-epiphytic cacti: Pilosocereus royenii, Melocactus intortus, Stenocereus fimbriatus, Leptocereus quadricostatus and Hylocereus trigonus. However, their ecology and natural history are still largely unknown. We visited a total of 12 sites during four years. We identified habitat preferences for each cactus species; recorded the incidence of fires and the invasion of grasses in these habitats. We also recorded bird-cactus interactions during 150 hrs. of observation. Observations on the reproduction biology of S. fimbriatus is provided for the first time, and differences of M. intortus morphology of two populations were assessed. Finally, we identify different threats to the Puerto Rican native cacti and dry forests. We also identified various questions on the basic ecology and biology of these cactus species that should be addressed in future works.

Cactaceae are a highly endangered plant family with economical and ornamental potential. One of its centers of diversity and endemism is in Eastern Brazil, including the Atlantic Forest in the state of Espírito Santo. The latest Brazilian global floristic inventory recorded 41 cactus species for this state, however an exclusive study about Cactaceae is still necessary to survey and describe the actual diversity of the family in the region and current threats acting upon the cacti. The aim of this study was to survey the species of Cactaceae in Espírito Santo state and analyze the threats suffered by them. A database produced from fieldwork, herbarium and literature research resulted in 908 georeferenced records which served for the production of distribution maps and to analyze sampling efforts and species richness. The richest grid cells were positively correlated to the best sampled cells. In total 38 native species of Cactaceae were found, including epiphytic, rupicolous, and terricolous life-forms. Several threats to the conservation of cacti in the region are acting to reduce the habitat of native populations. Our results indicate the need to include an effective sampling of cactus specimens in order to understand the real conservation of the species of this highly endangered family.

The typification of the names Agave convallis Trelease and A. dissimulans Trelease is discussed and clarified. We show that the two Trelease 4 specimens associated with the name A. convallis are not duplicates (they have different collecting dates). The Trelease 4 specimen dated 5 February 1905 (barcode MO-1128755; MO specimen number 3346866) is the lectotype of the name A. convallis, while the other Trelease 4 specimen dated 12 February 1905 (barcode MO-1256267; MO specimen number 3346867) is a syntype. We confirm the lectotypification of the name A. dissimulans, with one of the two Trelease 81 specimens dated 11 February 1905 (barcode MO-1128757; MO specimen number 3346870). The other Trelease 81 specimen, which is also dated 11 February 1905 (barcode MO-1128758; MO specimen number 3346869), is an isolectotype. The typification status of Trelease 82, which is also dated 11 February 1905 [barcode MO-1256273; MO specimen number 3346871], is that of syntype. All the Trelease specimens mentioned here are held in the Herbarium of the Missouri Botanical Garden (MO). For the sake of completeness we also refer to the typification, and clarify the etymology, of the name Agave kerchovei Lem. This species is a close relative of A. convallis and A. dissimulans.

Kalanchoe hirta Harv. was included in the synonymy of Kalanchoe crenata (Andrews) Haw. in the Flora of Southern Africa treatment of the family Crassulaceae. We here reinstate K. hirta as a good species. Descriptions are provided for K. hirta and K. crenata, and characters distinguishing them noted and illustrated. The regional geographical distributions of both species are mapped.

In this paper Ceropegia reflexa Hanacek, belonging to Ceropegia sect. Rhytidocaulon, is described. It is known from one locality in the Al Mahra Governorate of Yemen in the southern part of the Arabian Peninsula. This new species is characterized by long pedicels, reflexed corolla lobes and the unusual twisted cilia along the margins of the lobes. Ceropegia reflexa occurs together with C. fulleri in rocky parts of Jabal Fartak, but at lower altitudes and in less exposed places than C. fulleri. A key to the nine Arabian members of Ceropegia sect. Rhytidocaulon is provided.

Spines are an important component of cactus species. Besides providing protection from predation, they reduce heat loading, reduce transpiration, and aid dispersal of stem segments for vegetative propagation among others. Bark formation occurs on surfaces of more than twenty species of columnar cacti in the Americas. For all species tested, bark formation is related to direct sunlight exposure. Extensive bark coverage leads to premature death for saguaro cacti (Carnegiea gigantea). Preliminary evidence indicates that changes in areoles with spines occurred during the bark formation on C. gigantea. Four hundred, sixty-one paired photographic images of areoles of north- and south-facing surfaces of shoots with bark percentages on adjacent troughs in 2017 were analyzed to determine differences between north- and south-facing surfaces. As in past studies, south-facing surfaces had higher bark percentages (mean bark coverage 62%) than north-facing surfaces (mean bark coverage 19%). For north and south areoles, mean numbers of central spines were 2.70/1.55; radial spines 3.20/1.50; and apex spines 1.81/1.13, respectively. When data were pooled to compare numbers of central, radial and apex spines as well as spine color and spine thickness, all were significantly related with bark percentages. Decreases in numbers and characteristics of spines precede bark formation on adjacent troughs. Overall, the results show that crests deteriorate faster than adjacent troughs. To our knowledge, this is the first report to document changes in spine numbers and characteristics with bark coverage on a cactus species.

Most cacti in subfamily Cactoideae have a thick cortex vascularized by a network of cortical bundles. It was noticed that some cortical bundles had a leaf-like feature: clusters of terminal tracheids. The objective of this research was to examine a range of species and characterize the clusters. Of the 226 species examined in 85 genera, 105 (46.7%) had clusters of terminal tracheids. Species with clusters were widely distributed throughout the subfamily. A few genera were uniform, with all sampled species having clusters (Ariocarpus, Corryocactus) or with all sampled species lacking them (Armatocereus, Mammillaria, Melocactus). Most genera were variable (e. g., Cereus, Cleistocactus) having some species with terminal tracheid clusters and other species lacking them. Where present, the clusters consisted of short, broad tracheids (not vessel elements), one or several phloem poles, but never fibers or sclereids (except Strombocactus disciformis). Clusters were most likely to occur at the apex of a rib or tubercle, especially near an areole; they often also occurred along the face of a rib; they were least common at the sinuses between ribs. Without exception, they occurred within the palisade cortex or along its base but never deep within the cortex. No ecological or functional role was obvious.