Five exsiccata relating to three taxa of Costa Rican epiphytic cacti collected by W.C. Wercklé deposited at HMGBH and at NY preserved from the original material sent to Berger at La Mortola are studied, illustrated and compared with the descriptions included in literature. The isotype of Rhipsalis wercklei A.Berger [= Rhipsalis micrantha (Kunth) DC.] discovered at HMGBH is designated here with the determination of the identity of Rhipsalis frondosa Wercklé nom. nud. [= Pseudorhipsalis acuminata Cufod.] and Rhipsalis costaricensis Britton nom. prov. [= Pseudorhipsalis himantoclada (Rol.-Goss.) Britton & Rose].

Chromosome numbers are determined for 524 individuals belonging to 107 taxa, including nothotaxa, within Cactaceae. Chromosome morphology was uniform within and among species. Nine unnamed nothotaxa and one previously named nothotaxon, Cylindropuntia ×vivipara, have chromosome numbers reported for the first time, and new chromosome numbers are reported for three taxa. Five putative Cylindropuntia hybrids are reported here for the first time: C. alcahes var. gigantensis × C. lindsayi, C. bernardina × C. echinocarpa, C. leptocaulis × C. ramosissima, C. echinocarpa × C. ramosissima, and C. echinocarpa × C. ganderi var. ganderi. Two putative Opuntia hybrids of less-certain origin are reported here: O. azurea var. discolor × O. rufida, and O. chlorotica × O. engelmannii. Two putative hybrids are reported for Echinocereus: E. arizonicus subsp. arizonicus × E. bonkerae subsp. bonkerae and E. coccineus subsp. coccineus × E. yavapaiensis. All chromosome number determinations reported to date are tabulated for Cylindropuntia, Grusonia, and selected taxa within Echinocereus. The significance of these data is discussed, including apparent correlations among polyploidy, subdioecy, sexual reproduction, and apomixis. We introduce six new combinations, one nothospecies designation, and a lectotypification for one taxon.

In preparation for a monograph of Euphorbia in southern Africa, twelve new taxa are described.

In Euphorbia subsect. Medusea (Haw.) Pax & K. Hoffm. one new species, E. willowmorensis Bruyns and three new subspecies, E. arida subsp. camdebooensis Bruyns, E. friedrichiae subsp. pofadderensis Bruyns and E. multiceps subsp. tanquana Bruyns are described; two new subspecies, E. ferox subsp. calitzdorpensis Bruyns and E. pseudoglobosa subsp. vlokii Bruyns are described in Euphorbia ser. Meleuphorbia (A.Berger) Bruyns; one new subspecies, Euphorbia patula subsp. brucebayeri Bruyns is described in Euphorbia subsect. Dactylanthes (Haw.) Pax & K.Hoffm.

In Euphorbia sect. Articulofruticosae Bruyns one new subspecies, E. ephedroides subsp. gamsbergensis Bruyns is described.

In Euphorbia sect. Esula (Pers.) Dumort. one new species, E. corneliae Bruyns, is described from southern Namibia.

In Euphorbia sect. Euphorbia there are one new species, E. otavibergensis Bruyns; one new subspecies E. subsalsa subsp. otzenii Bruyns; and one new variety, E. lydenburgensis var. minor Bruyns.

In addition, in subsect. Dactylanthes the concept of Euphorbia patula Mill. is substantially re-configured and four subspecies are recognized, with E. anacantha Aiton and E. wilmaniae Marloth included as two of these subspecies.

The identity of Astroloba pentagona (Haw.) Uitewaal (Asphodelaceae: Alooideae), the type species of the genus Astroloba Uitewaal, is clarified. It is shown that the name A. pentagona can be applied to populations of Astroloba from north of the Swartberg Mountains in the Western Cape Province of South Africa. The history of the name A. pentagona is discussed, and the description of the species is amplified. An epitype is designated and a geographical distribution map is provided for the species.

A synopsis of the infrageneric classification of Astroloba Uitewaal (Asphodelaceae: Alooideae) is presented, and the 12 known species are assigned to two subgenera. Poellnitzia Uitewaal is reduced to subgenus rank in Astroloba, as A. subg. Poellnitzia (Uitewaal) Molteno & Gideon F.Sm., and three sections within A. subg. Astroloba, A. sect. Intercedens Molteno & Gideon F.Sm., A. sect. Inflata Molteno & Gideon F.Sm., and A. sect. Vastora Molteno & Gideon F.Sm., are recognised, all of which are described here. A new combination, A. spirella (Haw.) Molteno & Gideon F.Sm. based on Haworthia spirella Haw., is published here. An epitype is designated for this combination. The accepted species that are included in the infrageneric groupings are enumerated, along with an indication of their typification. Separate keys are provided to the subgenera, sections and species recognised in Astroloba.

A new species of Kalanchoe Adans. (Crassulaceae), K. crouchii Gideon F.Sm. & Figueiredo, is described from the Wolkberg Centre of Endemism, Mpumalanga Province, South Africa. The species is allied to K. luciae Raym.-Hamet, K. montana Compton, K. thyrsiflora Harv., and K. winteri Gideon F.Sm., N.R.Crouch & Mich.Walters, from which it can be readily separated on vegetative and reproductive characteristics.

Very little is known about the relations between aloes and soil metals, despite evidence that aloes often form dense populations on metalliferous soils. This study targeted eight rock outcrops where aloes dominated the vegetation to determine whether these succulents have a preference for soils rich in heavy metals and whether they accumulate any of these metals in their leaf tissue. Soil analyses suggested that densely populated rock outcrops are rarely characterised by high concentrations of heavy metals. Analyses of leaf material revealed no metal hyperaccumulators, with most species acting as excluders of most metals. The only metals to be reflected in leaf material to some degree across populations were copper (mean of 4 µg g^-1), iron (mean of 208 µg g^-1), manganese (mean of 342 µg g^-1) and zinc (mean of 31 µg g^-1)(all values are based on leaf dry weight). Aloe greatheadii plants from the ultramafic-peralkaline Koedoesfontein Complex in the Vredefort Dome contained the highest concentrations of Mn (558 µg g^-1) and were subjected to further sampling across four geological substrates to determine the limits of its accumulation ability (mean of 855 µg g^-1 on wehrlite). This aloe was found to be non-hyperaccumulating, but tolerant to elevated Mn concentrations in its tissue. The uptake of Mn from the soil was not so much influenced by soil available Mn, but rather by decreasing pH, and increasing electric conductivity and soil potassium.

47 accessions of the Delosperma-clade are analyzed using ITS and four chloroplast markers. With two exceptions, Frithia pulchra and Delosperma esterhuyseniae, all accessions are retrieved in a single, unsupported Delosperma s.l. clade. The main Delosperma s.str. clade is well supported and falls in three subclades, one comprising the two Mestoklema accessions, the other two mainly Delosperma accessions, but also Corpuscularia and Ectotropis. These genera are therefore subsumed under Delosperma. Trichodiadema accessions are retrieved in several places inside the Delosperma s.l. clade. The East African-Arabian Delosperma species are monophyletic if D. alpina from the Drakensberg is included; but they are not monophyletic with the species from Madagascar and Réunion. The species of the Central Plateau of southern Africa are also monophyletic and sister to the East African-Arabian species. Two new species, Delosperma heidihartmanniae and D. melepoense, are here described in the East African-Arabian clade.

Further field work in Gran Canaria (Canary Islands, Spain) yielded new records of escaped cacti. Opuntia elatior, O. engelmannii, O. phaeacantha, O. stricta, Oreocereus pseudofossulatus, Pilosocereus polygonus, Trichocereus cuzcoensis and T. pachanoi are reported for the first time from Gran Canaria. A spontaneous hybrid between two invasive species (O. ficus-indica and O. robusta) was recorded in two localities. Several of these taxa appear to be firmly established while others are considered casuals, at least at present. Austrocylindropuntia cylindrica – a species formerly considered doubtful in the Canary Islands – is confirmed from Gran Canaria. New records are presented for three recently detected, naturalized or invasive species: Cylindropuntia bigelovii, C. prolifera and Opuntia lindheimeri. All newly detected taxa are illustrated and a key for the identification of the opuntioid species reliably recorded so far in the Canary Islands is presented.

A new species of Aloe (Asphodelaceae) in Kenya is described as A. sergoitensis L.E. Newton and compared with A. elgonica. Aloe sergoitensis differs from A. elgonica by having forked teeth along its leaf margins, less densely-flowered racemes, and coral-red flowers that are smaller than those of A. elgonica. Its leaves are longer and have a slight bluish bloom.

The early nomenclature and typification of the name Aloe ferox Mill. (Asphodelaceae: Alooideae) is discussed and clarified. It is shown that a plate included in Munting (1727) is the lectotype of the name; we also designate an epitype. A previous neotypification of the name A. ferox was redundant.

Florivory reduces pollinator visits and plant fitness due to the elimination of gametes and floral reproductive organs. Longevity and floral synchrony favors escape from florivores and increases resources for pollinators. We study the effects of natural and experimental florivory and if synchrony can diminish it. We determined the floral longevity and phenology of a living rock cactus population in Tamaulipas, Mexico. Open flowers were counted to estimate floral synchrony using the Marquis index. Floral longevity was established (n = 21 flowers). Florivory frequency was recorded indicating the phase of the damaged flower (floral bud, open or closed flower) and the structure (perianth, stigma and anthers) of which some percentage of tissue was removed (25, 50 and 100%) (284 flowers and 150 floral buds; 245 individuals). Flowers with natural damage to reproductive organs and gametes were quantified to determine the direct effect of florivory. Variations in the frequency of pollinators were evaluated with a paired experiment of artificial florivory: whole flower (control) and flower with removal of 50% of the perianth; taxonomic group of pollinators and florivores was recorded and the activity they carried out. Floral longevity varies from one to three days. Flowering is synchronous (S = 0.53 ± 0.09). In the population, 10.2% of the flowers and 2.6% of the floral buds presented florivory, the perianth of the flowers is the most predated. Artificial florivory does not reduce the frequency of pollinators; we argue that visitors do not discriminate between damaged and intact flowers. Florivory does not limit the masculine function because pollen search is the main activity. A total of 2% of the structures were partially (stigma) or totally consumed by Coleoptera (Cryptorhynchinae) and Lepidoptera, reducing the fruit-set due to the death of the flower.