Vorontsova, M.S. (2018). Revision of the group previously known as Panicum L. (Poaceae: Panicoideae) in Madagascar. Candollea 73: 143–186. In English, English and French abstracts. DOI: http://dx.doi.org/10.15553/c2018v732a1

Panicoid grasses are ubiquitous across Madagascar, yet no complete and modern taxonomic framework has so far been attempted. This paper aims to establish and record species boundaries in the group previously recognised as the genus Panicum L. (Poaceace, Panicoideae), with simple panicoid spikelets and open panicle-like inflorescences. All specimens held at the K, P, and TAN herbaria were revised in addition to field work throughout the island. Species concepts were reconciled with those in tropical Africa. Recent phylogenetic research in Panicum s.l. has been incorporated and several species have been placed in Adenochloa Zuloaga, Trichanthecium Zuloaga & Morrone, and Urochloa maxima (Jacq.) R.D. Webster. Further species outside the Panicum s.s. clade will be ultimately transferred to other genera pending further research. A treatment of 32 species is presented, including an identification key, synonymy and typification for all names applied to specimens collected in Madagascar, species descriptions, illustrations, distribution maps, and full specimen citations. Twenty species (63%) are endemic to Madagascar and the nearby islands. Data on natural occurrence in Madagascar are presented but these are still tentative. Nineteen names are placed in synonymy for the first time; 38 lectotypes are designated.

Castillon, J.-P. & J.-B. Castillon (2018). A new threatened species of Euphorbia sect. Goniostema (Euphorbiaceae) from northern Madagascar. Candollea 73: 187–191. In French, English and French abstracts. DOI: http://dx.doi.org/10.15553/c2018v732a2

Euphorbia longitubicinicyathium J.-P. Castillon & J.-B. Castillon (Euphorbiaceae), a new species from northeastern Madagascar is described and illustrated with field photographs. The new species belongs to Euphorbia sect. Goniostema Baill. ex Boiss. and is morphologically related to non thorny species of the east coast of Madagascar (e.g. Euphorbia geroldii Rauh, Euphorbia robivelonae Rauh or Euphorbia thuarsiana Baill.) but differs by its larger dimensions, its habit and its long trumpet shaped cyathia.

Delage, A. (2018). Echium montenielluense (Boraginaceae), a new species endemic to Corsica. Candollea 73: 193–199. In French, English and French abstracts. DOI: http://dx.doi.org/10.15553/c2018v732a3

A plant belonging to the genus Echium L. (Boraginaceae), discovered on the serpentine ridges of Cap Corse is described, characterized morphologically and named Echium montenielluense Delage. Elements relating to its ecology and its demography are presented. Probably related to the Sardinian endemic Echium anchusoides Bachetta et al., the differences between the two taxa are highlighted.

Paradis, G., C. Piazza & Y. Quilichini (2018). Anchusa crispa subsp. valincoana Paradis, Piazza & Quilichini (Boraginaceae), a new subspecies endemic to Corsica. Candollea 73: 201–207. In French, English and French abstracts. DOI: http://dx.doi.org/10.15553/c2018v732a4

Anchusa crispa subsp. valincoana Paradis, Piazza & Quilichini (Boraginaceae), a new endemic subspecies of the littoral of the western coast of Corsica is described and illustrated. It includes four sub-populations around the Gulf of Valinco, near Propriano. It differs by several morphological characters from Anchusa crispa Viv. subsp. crispa, present on two sites of the Corsican east coast, south of Solenzara and in several localities of the north-west coast of Sardinia, notably by its reddish flowering stems, subglabrous lower surface of leaves, bracts with subglabrous upper surface and glabrous below and its flowers with dark blue corolla. It also differs from Anchusa crispa subsp. maritima (Vals.) Selvi & Bigazzi, a Sardinian endemic, located on some sites of the north coast of Sardinia, a taxon with brownish or greenish flowering stems, linear leaves and bracts with upper surface minutely pubescent.

Mathieu, G. (2018). Notes on ‘rabbit tail’ Peperomias (Piperaceae) with description of two new species. Candollea 73: 209–215. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2018v732a5

‘Rabbit tail’ Peperomia Ruiz & Pavón (Piperaceae) species are peculiar in the ellipsoid or globose shape of their inflorescences. Notes on three species of this group are presented. The taxonomic status of Peperomia clavigera Standl. & Steyerm. is discussed and two new species: Peperomia physostachya G. Mathieu from Ecuador and Peperomia sphaerostachya G. Mathieu from Colombia are described and illustrated.

Received: May 9, 2018. Accepted: August 15, 2018. First published online: November 5, 2018

Mazumdar, J. & M.W. Callmander (2018). Lectotypification of the N.L. Burman’s fern name Adiantum denticulatum. Candollea 73: 217–220. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2018v732a6

The fern name Adiantum denticulatum Burm. f. was published by Nicolaas Laurens Burman (1734–1793) in his Flora Indica: cui accedit series zoophytorum indicorum, nec non prodromus florae capensis in 1768. Original material of this name included specimens from his own herbarium (now conserved in Geneva under the acronym G-PREL) and an illustration from Leonard Plukenet's Phytographia. The history of the typification of this fern name is reviewed and a Franciscus Albertus Pryon collection from Java in G-PREL is designated as second-step lectotype.

Received: May 26, 2018. Accepted: August 24, 2018. First published online: November 5, 2018.

Applequist, W.L. (2018). A revision of the Malagasy species of Homalium sect. Blackwellia (Salicaceae). Candollea 73: 221–244. In English, English and French abstracts. DOI: http://dx.doi.org/10.15553/c2018v732a7

Homalium sect. Blackwellia Benth. (Salicaceae) is the largest and most widespread solitary-stamened section of Homalium Jacq. As part of a project to update the taxonomy of Homalium in Madagascar, a new revisionary treatment of the Malagasy species is presented and an identification key is provided. Fifteen species are recognized, of which four are newly described, and within Homalium axillare (Lam.) Benth. a subspecies, Homalium axillare subsp. delphinense (H. Perrier) Appleq., is recognized. Homalium acuminatifolium Appleq. is similar to Homalium axillare, but the leaves are usually lanceolate with a long-acuminate apex and the petals often spreading; it is native to the province of Toliara. Homalium longiracemosum Appleq. is distinguished by its long racemes and long, narrow, long-petioled leaves; it is endemic to the vicinity of Sainte Luce. Homalium fortunatii Appleq. and Homalium martialii Appleq. are similar to Homalium thuarsianum (Tul.) Baill. in having pubescent sepal glands and paniculate inflorescences. Both of these new species have usually elliptical to narrowly elliptical leaves and are native to northeastern humid forests. Homalium fortunatii has minutely pubescent young twigs, while Homalium martialii has sepals and petals always shorter than the calyx tube. Occasional hybridization is observed. Homalium microphyllum O. Hoffm. is not recognized and the type is believed to be a hybrid involving a species of Homalium sect. Odontolobus Warb.

Arana, M.D. (2018). New synonyms, typifications and excluded species in the Lycopodiaceae family of the flora of Paraguay. Candollea 73: 245–248. In Spanish, English and Spanish abstracts. DOI: http://dx.doi.org/10.15553/c2018v732a8

The typification of 4 names described in the Lycopodiaceae family from Paraguayan collections in the genus Lycopodium L. is presented. Three lectotypes are designated for: Lycopodium alopecuroides f. integrum Hassl., Lycopodium alopecuroides f. intermedium Hassl., Lycopodium carolinianum var. paraguariense Hassl. Four new synonyms are proposed. Eight species are excluded from the flora of Paraguay.

Price, M.J. (2018). Two hundred years in the dark: A type for the moss Encalypta crispata. Candollea 73: 249–255. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2018v732a9

The historically important Hedwig-Schwägrichen collection in G contains type material linked with the moss names of Johannes Hedwig. These originate from species that he described as new to science, or that were ascribed to him when his 1801 publication Species muscorum frondosorum was designated as the starting point for moss names (excepting Sphagnaceae). A small number of the Hedwig type specimens have not been found within the G holdings, amongst which was Ptychomitrium crispatum (Hedw.) A. Jaeger (Ptychomitriaceae). This species was newly described by Hedwig in his 1801 work, under the name Encalypta crispata Hedw., based on material from the Cape of Good Hope in South Africa that was collected by the Swedish naturalist Carl Peter Thunberg. The specimen used by Hedwig to describe this species was recently found in one of the original Hedwig herbarium storage cases, amongst a set of reference material that had not been accessioned into the herbarium. After more than two-hundred years in obscurity, the newly rediscovered holotype material of Ptychomitrium crispatum is discussed herein. A description and illustration of Ptychomitrium crispatum is given, based on the type and other material from South Africa.

Received: June 21, 2018. Accepted: August 30, 2018. First published online: November 5, 2018

Stone, R.D. (2018). Lijndenia meeusei, the correct name for the species previously known as L. lutescens (Melastomataceae, Olisbeoideae). Candollea 73: 257–259. In English, English and French abstracts. DOI: http://dx.doi.org/10.15553/c2018v732a10

Under the principle of priority, the new combination Lijndenia meeusei (H. Perrier) R.D. Stone (Melastomataceae, Olisbeoideae) is the correct name for the species previously known as Lijndenia lutescens (Naudin) Jacq.-Fél. Use of the superfluous name Lijndenia memecyloides R.D. Stone must therefore be abandoned.

Chaowasku, T., A. Damthongdee, H. Jongsook, D.T. Ngo, H.T. Le, D.M. Tran & S. Suddee (2018). Enlarging the monotypic Monocarpieae (Annonaceae, Malmeoideae): recognition of a second genus from Vietnam informed by morphology and molecular phylogenetics. Candollea 73: 261–275. In English, English abstract. DOI: http://dx.doi.org/10.15553/c2018v732a11

Recent botanical expeditions in central Vietnam yielded an unknown species of Annonaceae that could not be confidently identified to subfamily, tribe, and genus. Preliminary BLAST^® searches based on plastid data have suggested that this taxon is genetically closely-related to the following tribes of subfamily Malmeoideae: Malmeeae, Fenerivieae, Maasieae, Phoenicantheae, Dendrokingstonieae, Monocarpieae, and Miliuseae. Using representatives of Piptostigmateae, another tribe of Malmeoideae, as outgroups and including representatives of all other tribes of Malmeoideae, molecular phylogenetic analyses of seven combined plastid markers (rbcL, matK, ndhF, ycf1 exons; trnL intron; trnL-trnF, psbA-trnH intergenic spacers) inferred the enigmatic Vietnamese taxon as belonging to the monotypic tribe Monocarpieae. Detailed morphological comparisons between this taxon and its sister group, Monocarpia Miq., warranted the recognition of a second genus of Monocarpieae to accommodate our unknown taxon: Leoheo Chaowasku with a single species, Leoheo domatiophorus Chaowasku, D.T. Ngo & H.T. Le. The morphology of the new genus agrees well with the diagnostic traits of Monocarpieae, e.g., a percurrent tertiary venation of the leaves, a highly reduced number of carpels per flower, enlarged and lobed stigmas, multiple ovules/seeds per ovary/monocarp, considerably large monocarps with a hardened pericarp when dry, and spiniform ruminations of the endosperm. However, the new genus does not exhibit two characteristic features of Monocarpia: terminal inflorescences and generally distinct intramarginal leaf veins. In addition, the new genus possesses three autapomorphic characters: hairy domatia on the lower leaf surface, longitudinal ridges on the monocarp surface, and subsessile monocarps with a stout stipe. The tribe Monocarpieae is consequently enlarged to include the genus Leoheo. The enlarged Monocarpieae, along with the recently established monotypic tribe Phoenicantheae and two other related tribes, Dendrokingstonieae and Miliuseae, are discussed.

Received: November 4, 2017. Accepted: August 30, 2018. First published online: November 23, 2018.

Zemagho, L., O. Lachenaud & B. Sonké (2018). Four new species of Sabicea (Rubiaceae) from tropical Africa, with additional notes on the genus. In English, English and French abstracts. Candollea 73: 277–293. DOI: http://dx.doi.org/10.15553/c2018v732a12

Four new species of Sabicea Aubl. (Rubiaceae) from tropical Africa are described and illustrated: Sabicea desseinii Zemagho, O. Lachenaud & Sonké from Cameroon, Gabon and Equatorial Guinea, Sabicea ezangae Zemagho, O. Lachenaud & Sonké from Gabon, Sabicea jongkindii Zemagho, O. Lachenaud & Sonké from Liberia and Ghana, and Sabicea uniflora Zemagho, O. Lachenaud & Sonké from Gabon. Their affinities are discussed, and the conservation status of each species is assessed. Sabicea speciosissima K. Schum. is excluded from the genus, neotypified, and synonymised with Rothmannia octomera (Hook.) Fagerl. Three other species are sunk into synonymy: Sabicea gigantea Wernham with Sabicea dewevrei De Wild., Sabicea arachnoidea Hutch. & Dalziel with Sabicea discolor Stapf, and Sabicea neglecta Hepper with Sabicea speciosa K. Schum. Lectotypes are designated for these six names.