The pantropical genus Peperomia consists of approximately 1,600 species with highest diversity in the Neotropics, especially in the Andes of Peru. Our continuous field work in this country shows that a considerable amount of new species still await discovery. Following our studies of the tuberous species of Peperomia subgenus Tildenia from the Andes, Central America and Mexico, we now tackle the closely related clade of terrestrial succulent window-leaved Peperomia species. This group currently consists of 31 accepted taxa, and we here describe and illustrate 10 new species and one variety, entirely based on observations in the field and in our ex situ living collections. Distribution, habitat and phenology data as well as detailed comparisons with other species are also included.

Two recently discovered members of the South African genus Cleretum N.E.Br. are described: C. bruynsii Klak and C. patersonjonesii Klak. Cleretum bruynsii occurs along the edge of the winter-rainfall region, between Namaqualand and Bushmanland in the Northern Cape, from north-east of Springbok to the north-eastern edge of the Kamiesberg. This species is characterized by inconspicuous yellow flowers on short pedicels. Its sister species, C. patersonjonesii, is endemic to the Kamiesberg in Namaqualand and possesses large yellow flowers on long pedicels. The two new species are closely allied to C. schlechteri and C. papulosum from which they differ by their more papillate, spoon-shaped leaves and the absence of a false septum in the fruits. A key to the 14 species of Cleretum is provided.

As an introduction to a series of contributions on the genus Gibbaeum N.E.Br., a review of the current taxonomic knowledge of the genus and open problems is given. The second part clarifies the intricate taxonomic history of Gibbaeum haagei. Gibbaeum haagei Schwantes ex H.Jacobsen 1935. was invalidly published and is a synonym of G. petrense (N.E.Br.) Tischer. Gibbaeum haagei Schwantes 1938. was validly published and misidentified by Glen (1974) and subsequent authors, as the white-tomentose Gibbaeum species from the Swellendam region (Western Cape Province, South Africa). Glen wrongly treated G. haagei Schwantes 1938. as a later illegitimate homonym of the earlier G. haagei Schwantes ex H.Jacobsen 1935. nom. inval. and proposed the new species G. austricola Glen (‘austricolum’) nom. inval. for the whitetomentose species from the Swellendam region. This prompted Hartmann (2001) to publish G haaglenii H.E.K.Hartmann as a replacement name which is illegitimate. Here it is shown that G. haagei Schwantes 1938 as well as G. haaglenii are synonyms of G. velutinum (L.Bolus) Schwantes. The white-tomentose species from the Swellendam region was published as G. haagei var. parviflorum L.Bolus, but is as yet without a valid name at the species level. As a new starting point, it is described here as G. hartmannianum Thiede & Niesler sp. nov.

A new species, Sedum brachetii Reyes, Islas et González-Zorzano, is described from Guerrero, Mexico. Placed within the section Pachysedum, S. brachetii differs from its closest comparable relatives S. clavatum, S. orbatum, S. cuspidatum and S. ocuilense in stem size, leaf structure, inflorescence size and nectary color. Figures of the holotype are provided.

Sedum kristenii Reyes, González-Zorzano & Etter is described as a new species from the Mexican state of Durango. It belongs in the group Americana of the section Sedum and is related to Sedum lumholtzii, Sedum copalense and Sedum bellum, from which it differs in roots, nectary color, and the size of stems and leaves.

Echeveria Juliana is described as a new species based on collections in the Rio Piaxtla Canyon, in the Sierra Madre Occidental near the border between the Mexican states of Sinaloa and Durango. This species appears to be related to E. tobarensis from Durango. It differs in the size of the rosette, its pale pink color, shape and pruinosity, as well as corolla size, color of the carpels, and its obovate leaves. The new species grows at an uncommonly low altitude of 360 m (1080 ft) in tropical deciduous forest. It belongs into the series Urbiniae as it lacks an evident stem or tuberous roots, and by the possession of a secund inflorescence and a long urceolate corolla.

Mona Island provides an important habitat for an interesting Caribbean xeric flora, which is noted for prominent Cactaceae as well as other succulent and pachycaulous plant species. A literature review demonstrated the need for documentation of this unique xerophytic flora. Here, we detail its succulent flora, and provide photographic documentation, literature review, specimen citations and field observations, to address that need.

Chromosome counts of members of the Opuntieae were carried out to further our understanding of ploidal levels, species boundaries, and evolutionary patterns within this group of stem succulents, which has been well-studied cytologically and is well known for hybridization and polyploidy. Here we counted chromosomes of 53 taxa in 4 genera (Consolea Lem., Nopalea Salm-Dyck, Opuntia Mill., and Tacinga Britton & Rose). Thirty of these counts are the first for a given taxon, and six counts represent a different ploidy for a taxon than has been reported previously. We also present a review of chromosome counts reported for Opuntieae. Ploidy in these taxa ranged from diploid, 2n = 2x = 22, to 20-ploid, 2n = 20x = 220. Of the 164 species in the Opuntieae for which chromosome counts have been carried out, including our new counts, 26.2% are diploid, 13.4% are both diploid and polyploid, and 60.4% are polyploid reiterating that the frequency of genome duplication in the group is far more common than diploidy.

Opuntia ventanensis A. Long (Opuntioideae, Cactaceae) is described as a new species from the Province of Buenos Aires, Argentina. The taxon is distinguished from its closest congeners, O. salmiana and O. aurantiaca, by characters of stem, interareolar area, spine length, flowers and fruit. Figures of the holotype are provided.

Understanding soil seed-bank dynamics of endangered species is crucial for their effective management and conservation. Whether or not seeds of Harrisia fragrans Small, a U.S. endangered cactus endemic to Florida (USA) form persistent soil seed-banks or withstand drying and/or freezing under storage conditions was unknown. We conducted a seed burial experiment with seeds collected from three sites (North, Middle, and South) within the Savannas Preserve State Park, FL, USA. We buried the seeds in plots with three light conditions (sun, partial sun, and shade) at each of the three sites and tested their viability in germination trials after 3.5, 8, 11, 16, 19 and 23 months of burial in soil. Buried seeds remained alive throughout the 23 months of the study period with germination ranging from 64 to 100%, which suggests that this species forms a persistent soil seed-bank. Microhabitat conditions markedly affected seed-bank size and subsequent seed viability. Seeds from the South site exhibited higher and faster germination than seeds from the Middle or North sites. We also evaluated if H. fragrans seeds could withstand dry storage under low relative humidity (RH) and low temperature. In the laboratory 76% of seeds stored under 12% RH and -20°C for 1 and 24 weeks germinated faster than seeds stored under 21–23°C and 50% RH. Thus, the capacity of Harrisia fragrans to form a persistent soil seed bank influences population persistence. Its ability to be stored in orthodox ex-situ conditions offers viable options for its future conservation and regeneration.

Harrisia is a genus of cacti native to South America and the Caribbean. Herbarium specimens, field studies, and cultivated plants were used to revise the genus. Harrisia caymanensis is described from the Cayman Islands. Typifications of 10 names of Harrisia are designated here. The type of H. taetra is clarified. Four names are newly synonymized. An identification key is provided for the 18 recognized species.

Gymnocalycium esperanzae Řepka and Kulhânek, has been recently described from the north central part of Argentina. In this paper the phylogenetic position and hybrid origin of this taxon are explored. Plant material of the supposed parental species was included in phylogenetic analyses with other members of three subgenera of the genus. The results of molecular analyses (cpDNA markers trnL-F, matK and AFLP) showed that G. esperanzae is closely related to members of the subgenus Trichomosemineum, especially G. bodenbenderianum and G. quehlianum. The second supposed parental species, G. castellanosii subsp. armillatum, was separated on a different branch in the tree. According to the special features of its seeds, which are similar to those of G. castellanosii, it clearly belongs to the subgenus Scabrosemineum. Also, molecular data were compared with morphological characters of its supposed parental species: G. bodenbenderianum (subgenus Trichomosemineum) and G. castellanosii subsp. armillatum (subgenus Scabrosemineum), which both grow near the locality of G. esperanzae. G. esperanzae has a very particular set of morphological features, some unique, others intermediate or more inclined to G. bodenbenderianum. Chloroplast DNA sequence analysis and AFLP analysis in combination with morphological features of all three species reveal a hypothesis of a hybrid origin of G. esperanzae.

The genus Trichocereus is represented by 19 taxa (12 species, 5 subspecies and 2 varieties) in Chile, 13 of them endemic to this country. These occur from the regions of Arica and Parinacota on the border with Peru, to the region of Maule, the IV Region of Coquimbo presenting the highest taxonomic richness. Its species are a dominant feature of the landscape and define phytogeographic regions. This taxonomic study has yielded iconographies, original descriptions, detailed descriptions, taxonomic comments, information on distribution and habitat, exsiccata, nomenclature, and three keys for the identification of species, subspecies and varieties. This treatment provides an updated synonymy including eight new synonyms; a new combination, Eulychnia coquimbana (Molina) S. Albesiano; three taxonomic level changes: (1) Trichocereus chiloensis subsp. australis (F. Ritter) S. Albesiano, (2) Trichocereus chiloensis subsp. eburneus (Phil. ex K. Schum.) S. Albesiano, and (3) Trichocereus chiloensis subsp. panhoplites (K. Schum.) S. Albesiano; three new names: (1) Trichocereus faundezii S. Albesiano, (2) Trichocereus pectiniferus S. Albesiano, (3) Trichocereus undulosus S. Albesiano; and thirteen neotypifications.

During the ongoing studies of the Crassulaceae family for the Flora of Veracruz (Mexico), we found two new species of Crassulaceae (Echeveria uxorium and Sedum jarocho), and eight new records for the state: Crassula connata var. connata, Echeveria bifida, E. coccinea, E. halbingeri, Sedum corynephyllum, S. ebracteatum, S. guatemalense, and Villadia patula. Data on the distribution and habitat of each species are given.