Matucana rebutiiflora is described as a new cactus species from Peru. It is the third species in the genus to bear symmetrical flowers which are probably pollinated by bees rather than humming birds. The habitat is an area favoured by local people for agriculture so threatening this remarkable new taxon.

Ferocactus wislizeni subsp. ajoensis is described as a new subspecies, and documented from the counties of Pima, Pinal, Maricopa and Yuma, Arizona, USA. It is distinguished from the type subspecies of F. wislizeni by its slender stem proportions, longer, denser and more robust spines and earlier and longer flowering period during the summer months. Unlike the type subsp. wislizeni that is found mostly on sandy and rocky soils, the characteristic habitats of subsp. ajoensis are the flat basin floors dominated by silts and clays.

The Horn of Africa is rich in succulent plants, yet the flora in some parts of the region remains under-explored, owing largely to political instability and inaccessibility. The Republic of Djibouti is a relatively small, politically stable country where botanical studies continue to identify new species records and new taxa. Here, we focus on the genus Aloe L. (Xanthorrhoeaceae subfamily Asphodeloideae) in Djibouti. Recent field surveys resulted in five new species records for the country (A. rigens Reynolds & Bally, A. macrocarpa Tod., A. eumassawana Carter, Gilbert & Sebsebe, A. ericahenriettae McCoy and A. djiboutiensis McCoy), in addition to the three taxa included in the treatment for the Flora of Djibouti (Aloe trichosantha A.Berger, A. aff. trichosantha and A. mcloughlinii Christian). We present notes on the determination, distribution and habitats of the nine Aloe species recorded in Djibouti.

A new species of Borzicactus, B. hoxeyi, is described. First observed in 2010, this small inconspicuous species, presently only known with certainty from the Morro de Sama on the arid southern Peruvian coast is distinct from all other members of the genus because of its unique flower morphology. It is also geographically disjunct from other Borzicactus species and it extends the range of the genus southwards by approximately 100km.

Solitary plants of the putative intergeneric cross Oreocereus celsianus × Echinopsis tarijensis were found on two independent occasions in the same general region of S Bolivia (Dept. Potosí). The plants are described and illustrated. They are intermediate in general appearance and flower characters between the supposed parents, and appear to be sterile. The importance of intergeneric and interspecific crosses in the evolution of Cactaceae is briefly discussed, and the relative ease with which intergeneric hybrids can be artificially obtained in cultivation is contrasted with the apparent rarity of naturally occurring intergeneric hybrids. Based on available evidence, the impact of natural intergeneric hybridization on cactus evolution appears to be limited.

Vivipary implies an active embryonic development with seed germination in the mother plant. The viviparous species are concentrated mainly in tropical and coastal areas with temporary flooding; thus, salinity and moisture are the main factors related to vivipary. This reproductive strategy is a rare event in the Cactaceae; however, vivipary in this family has been reported for 53 species (3.7% of the family). Ferocactus herrerae is a viviparous cactus native of northwestern Mexico, for which it has been suggested that the overall proportion of viviparous plants is higher in coastal flooding areas relative to halophytic, nonflooding areas. Thus, in this research we determine the correlation of the salinity/moisture with the vivipary incidence in Ferocactus herrerae. We performed Independence Tests between the reproductive types (viviparous/non-viviparous) and three salinity/ moisture conditions in experimental sites in northern Sinaloa, México. We had irrigation (Pueblito site), irrigation-salinity (UAS site), and control (San José site) sites. The Pueblito and UAS sites had 82% and 100% of viviparous plants compared with 56% recorded in the control. The UAS site produced 7 fruits per plant on average, with 43% viviparous, whereas the San José and Pueblito sites produced 18 fruits per plant with viviparous averages of 7.6% and 16.7% respectively. These results confirm that humid tropical and coastal environments are important in the development of vivipary in F. herrerae.

Several species of Agave L. (Agavaceae / Asparagaceae) have intricate nomenclatural histories, given that material imported into Europe from their New World habitats took several years, if not decades to flower, resulting in hasty and cryptic descriptions often being based on vegetative material only. Furthermore, multiple authors sometimes, but not always, used the same binomials to refer to plants known in cultivation, making it important to clarify and establish correct author citations to determine which species are referred to. In this paper we clarify the use of the well-known names Agave applanata Hort. ex K.Koch, A. verschaffeltii Lem. ex Jacobi and A. ghiesbreghtii Hort. ex Jacobi. In addition, notes are provided on 12 further species names that K. Koch established and, where appropriate, furnished by him with descriptive statements in an often overlooked paper that he published in 1862.

Based on earlier work on the construction of the diadem, the name-giving feature of the genus Trichodiadema, the results of fresh investigations with a focus on plants that lack “true diadems” are presented. The possession of stiff prickly bristles can be understood to form the probable synapomorphy of all members of the genus, the main chemical component being suberin. More extensive studies of flowers and capsules permit a subdivision of the genus into two subgenera, and T. subg. Gemiclausa is described here as a new subgenus. A key to the six included species is given, and all species of the new subgenus are described.

Apart from two present-day centres of high species diversity, one in southern Africa and the other in Mexico, the Crassulaceae, a large family of mainly herbaceous leaf succulents, is also well-represented in Europe in terms of both genera and species. One of these genera, the predominantly continental European genus Sedum L., has for a long time been acknowledged as in need of being split into smaller, more homogenous genera. The recent implementation of some of these taxonomic proposals is here applied to the crassuloid taxa of continental Portugal (islands excluded), with particular reference to Petrosedum Grulich. An updated and expanded checklist of the genera and species of Crassulaceae occurring in Portugal is provided, along with notes on differences between Sedum and Petrosedum. Thirty-six species of Crassulaceae are now recorded for Portugal (continent, excluding islands), of which 14 are introduced.

The taxonomic and nomenclatural history of Lobivia chrysochete (Werdermann) Wessner is reviewed and a lectotype established. Biogeographic, morphological and genetic information is provided to support the assertion that one member of the group, Lobivia chrysochete var. minutiflora Rausch, should be considered a distinct species. Illustrations of both species in habitat and cultivation are presented.

Quantitative and qualitative characters were collected from 11 natural populations of four taxa: G. prochazkianum, G. simile, G. simplex and G. bicolor. In this paper the results of one-way ANOVA of 11 quantitative characters using taxon identity as the single predictor, and results of PCA are published. Seven qualitative characters were evaluated out of a morphometric analysis.

The results show a mostly intermediary position of G. simile between G. prochazkianum and G. simplex, whereby G. simile is classified here as a intermediate type at subspecies level (likely to be of hybrid origin between the assumed parents G. prochazkianum and G. simplex, which grow close to each other). G. simplex, which did not have a valid name, is classified as a subspecies of G. prochazkianum for its morphological and geographical proximity, as well as its genome size, and is described here.

For the identification of the taxa also flow cytometry was used, which demonstrated diploid ploidy level and a high similarity of genome sizes of all the taxa. Notes on the morphological differences between G. bicolor Schütz nom. inval. and G. prochazkianum subsp. simplex are added.

The combination Aloe fievetii var. altimatsiatrae (J.-B. Castillon) J.-B. Castillon is validly published to rectify a mistake made in 2009. The synonymy of Aloe newtonii J.-B. Castillon is clarified.

In a comprehensive study of the genus Drosanthemum, material was detected that differs fundamentally in molecular and morphological character states from the genus proper. Since it can neither be placed in any of the existing genera of the tribe Ruschieae, a new genus is described here, Knersia H.E.K.Hartmann & Liede gen nov., with K. diversifolia (L.Bolus) H.E.K.Hartmann & Liede comb. nov. as the single species.

We show that of four previously unrecorded, but recently unearthed names in Aloe L. (Asphodelaceae: Alooideae), none has an impact on the species-rank nomenclature of the genus as currently accepted. Although nomenclatural stability is not here impacted, we argue that such long-hidden names that are now visible as part of the nomenclature applicable to Aloe have the potential to unnecessarily or inappropriately disrupt the status quo. The same will apply to other taxa for which the existence of historical names has been recorded. A formal mechanism must be introduced through the Code to lessen or, ideally, entirely prevent such names displacing ones long in use.

Initiated by the description of a new species in Delosperma closely resembling members of the genus Ectotropis, an investigation was begun again to determine the circumscription of Ectotropis. As a result, Ectotropis as a genus can be confirmed, based mainly on flower and fruit morphology, and two species are recognized: E. alpina N.E.Br. and E. seanii-hoganii (Niederle) H..K.Hartmann & C. Schröder, comb. nov.

We argue that the names Aloe hexapetala Salm-Dyck, A. drepanophylla Baker, Aloe chloroleuca Baker and Aloe platylepis Baker should not be regarded as competing with the name Aloe speciosa Baker. The latter name is well-known, widely used, and can be easily linked to natural populations of an aloe that is widespread in South Africa's Western and Eastern Cape Provinces. The other names are to be regarded as insufficiently known.

The putatively closely related cactus genera of Coleocephalocereus, Micranthocereus, Cereus, Monvillea, and Stetsonia have a wide range in specialization of reproductive portions of the shoot, from cephalium to pseudocephalium to no specialization. After briefly summarizing the shifting uses of the terms ‘cephalium’ and ‘pseudocephalium’, I provide gross morphological evidence that Coleocephalocereus purpureus has a true cephalium that is formed of a continuous swath of bristles and hairs, with its underlying thick cortex of parenchyma replaced by a narrow layer of cork. By contrast, Micranthocereus streckeri has a pseudocephalium composed of nothing more than larger hairier areoles in which the underlying epidermis is still photosynthetic and the underlying cortex is still a thick layer of parenchyma without any noticeable cork.

In harsh environments some plant species grow under the shelter of other plants. This spatial association known as nurse-protégé interaction is common in arid and semiarid environments. In here we studied the spatial association of six cacti (Ariocarpus retusus, Astrophytum asterias, Echinocactus texensis, Cylindropuntia leptocaulis, Sclerocactus scheeri and Mammillaria heyderi) and one Asparagaceae (Manfreda longiflora) to other plant species. We determined whether they occurred more often under other plants, if they grew very near them or at an angle that provided shade. Manfreda longiflora always grew under the canopy of other plants. Ariocarpus retusus, Astrophytum asterias, Cylindropuntia leptocaulis, and Mammillaria heyderi occurred equally under nurse plants and in open spaces. Echinocactus texensis and Sclerocactus scheeri occurred more often than expected in open areas, but Sclerocactus scheeri occurred shaded from the afternoon sun. We argue that nurse-protégé interactions are less common in our study site due to higher rainfall than that in other studied environments.

The combination Kumara plicatilis (L.) Klopper & Gideon F.Sm. recently published for the fan aloe [Aloe plicatilis (L.) Burm.f.], is a synonym of Kumara plicatilis (L.) G.D.Rowley, the latter having priority due to earlier valid publication.

The genus Orbea has had a chequered and convoluted history, usage, and interpretation by various authors since the name was originally proposed by Adrian Haworth in 1812. The following account is an attempt to present the background to these various issues in order to suggest what taxa are appropriate for inclusion in it. Two existing subspecies are raised to species rank, Orbea kaokoensis (Bruyns) Plowes, and O. orientalis (Bruyns) Plowes, and one taxon, currently treated as a variety, is recognized as a subspecies, O. verrucosa subsp. fucosa (N.E. Br.) Plowes.