Diane M. Bridson

The reinstatement of Psydrax (Rubiaceae, subfam. Cinchonoideae tribe Vanguerieae) and a revision of the African species

The genus Psydrax Gaertn. is reinstated and the genera Mesoptera and Mitrastigma placed in synonymy; two subgenera are recognised, the palaeotropical subgen. Psydrax and the African subgen. Phallaria. In all, 36 African species are recognised; 10 new species and 3 new subspecies are described; 26 new combinations are made, 22 at specific level, 3 at subspecific level and one at varietal level; new synonomies are indicated. Distributions are given and specimens cited for new taxa. In addition one new combination from Malaya and one from Australia are made for nomenclatural reasons.

Studies in African Rubiaceae-Vanguerieae: a new circumscription of Pyrostria and a new subgenus, Canthium subgen, Bullockia

In two preceding papers (Bridson 1985 & 1986), concerned with Vanguerieae, Psydrax Gaertn. and Keetia E. P. Phillips, both chiefly characterised by narrowly cylindrical stigmatic knobs borne on long styles, were separated from Canthium sensu lato. Most taxa remaining in Canthium sensu lato have the stigmatic knob + as wide as long and the style sub-equal to or slightly longer than the corolla-tube; however, considerable diversity is still present, species, for the most part, forming natural groups (either generic or infrageneric). The African representatives of two such groups are revised here, one, Pyrostria, at generic rank, and the second as a subgenus of Canthium. Originally the genus Pyrostria, restricted to the Mascarenes, accommodated species with umbellate inflorescences enclosed in bud by persistent paired connate bracts, unisexual flowers and plurilocular ovaries. Subsequently, however, many 2-locular Madagascan species have been placed in Pyrostria. Species from the African mainland show little significant difference from Madagascan Pyrostria, apart from including some species with hermaphrodite flowers. The African species are currently dispersed amongst Canthium (including Plectronia sensu auctt.), Rytigynia and Dinocanthium, and although the combination in Pyrostria has been made for the well known Afro-Madagascan species, Canthium bibracteatum (Cavaco 1968), it has not hitherto been adopted in Africa.

The genus Canthium (Rubiaceae―Vanguerieae) in tropical Africa

The genus Canthium subgen. Canthium is discussed and recognized as occurring in tropical Africa; three additional tropical African subgenera are recognized: subgen. Bullockia (Bridson 1987), subgen. Afrocanthium and subgen. Lycioserissa (both Bridson 1991), the latter two being revised here. A key is provided to include the genera previously segregated from Canthium (Bridson 1985, 1986, 1987, 1987a) and the tropical African subgenera of Canthium. One new combination at subspecific rank is made, and one new variety described in subgen. Canthium, 3 new species and 1 new subspecies described in subgen. Afrocanthium, and 1 new subspecies described in subgen. Lycioserissa; one new name is provided for a species unplaced subgenerically. Keys are included for the species of subgen. Afrocanthium and subgen. Lycioserissa. Distributions are given and citations included for new taxa. A complete list of all African epithets in Canthium and Plectronia with their current position is appended (Appendix 2).

Studies in Coffea and Psilanthus (Rubiaceae subfam. Cinchonoideae) for Part 2 of 'Flora of Tropical East Africa': Rubiaceae

During the course of the revision of the genus Coffea L. for the F.T.E.A. Rubiaceae vol. 2 it became apparent that some of the East African species dealt with by Chevalier (Les Caf6iers du Globe 3 (1947)) were in need of revision, while other epithets had subsequently been misapplied. Not only was the number of indigenous species of Coffea sensu stricto very much larger than at first anticipated, but one species of Coffea falling outside the definition of Coffea sensu stricto (see pages 852-4) and three species of the closely related genus Psilanthus (see pages 854-8) were found. Although adequate material to allow full formal description of five new species of Coffea is known, an additional 11 taxa (probably worth specific rank) are also included. Because of the considerable economic importance of Coffea such novel taxa have been treated in as much detail as possible so as to permit informed field studies which could lead to re-collection of both good herbarium specimens and living material for experimental culture. As well as fulfilling the necessary nomenclatural requirements for the description of new taxa and the reassessment of existing taxa, this paper includes dichotomous and multi-access keys and a character list which will enable it to be used as a field guide by personnel with a moderate knowledge of botany. The three commonly cultivated species C. arabica, C. canephora and C. liberica have not been dealt with fully in this paper, although they have been included in the keys and the character list. In addition to cultivated plants, wild plants can be found as follows: C. arabica: SE Sudan (Boma Plateau); SW Ethiopia & N Kenya (Mt Marsabit) (fide Friis in Proc. 9 Plenary Meeting of A.E.T.F.A.T.: 63 (1979)). C. canephora: Sudan, Uganda & Tanzania (Bukoba District). C. liberica (closest to C. liberica var. dewevrei (De Wild. & Th. Dur.) Lebrun including C. excelsa Chev.): Sudan & Uganda. Since most of the characters separating the species in Coffea are generally weak and variable and so many taxa are imperfectly known, definite opinions on the relationships between species can only be made with difficulty. Furthermore, it would be unwise to recognise infrageneric taxa in this paper as the West African and Madagascan species have not been considered. In my opinion Chevaliers subsection Mozambicoffea is artificial, especially with regard to the inclusion of C. eugenioides which is much closer to C. canephora

A Short Revision of Rutidea (Rubiaceae)

While preparing an account of Rutidea DC. for the Flora of Tropical East Africa, Rubiaceae Vol. 2, it became apparent that since the time of Hierns account of the genus for the Flora of Tropical Africa (1877), a high proportion of specimens had been incorrectly identified and several epithets consistently misapplied. As both types of error have found their way into print some remedial treatment of the genus as a whole is required; also many new taxa (largely unrepresented at Kew) have come to light and are in need of formal description where sufficient material is available. This work is in the form of a short revision and is based on the morphological study of herbarium specimens. A key to species and subspecies is provided; full synonymies and distributions are given for all species; short citations are given for new taxa, rare taxa and for taxa which have a history of confusion or misidentification; descriptions are given for new taxa only. Table I, pp. 250-1 shows the occurrence of the more significant characters for each species and is intended both to help compensate for the lack of descriptions and to indicate the relationships between species; it may also be used as a multi-access key. All species are illustrated and distribution maps for certain groups included. Imperfectly known and excluded species are listed. An index to epithets used in this paper is given. All specimens cited below have been seen unless otherwise stated. Herbarium indications for duplicates of gatherings thought to exist in other herbaria have not been given when only the Kew duplicate has been seen. I wish to thank the Directors of the following Herbaria for sending material on loan-Berlin-Dahlem (B), British Museum (Nat. Hist.) (BM), Brussels (BR), Coimbra (COI), East African Herbarium (EA), Hamburg (HBG), Lisbon (LISC) and Paris (P). I also wish to thank Mr Robbrecht (of BR) for making his invaluable bibliographical index to Rutidea available to me, and Dr. B. Verdcourt for general advice and (together with Mr. H. K. Airy-Shaw) for help with the Latin.

The recognition and recircumscription of the African genus Multidentia (Rubiaceae-Vanguerieae)

The genus Multidentia Gilli is reinstated and the circumscription enlarged to include taxa formerly dispersed amongst Canthium sensu lato, Vangueriopsis and Pygmaeothamnus. In all 11 species are recognised; 7 new combinations are made at specific rank and one at varietal level; 2 new species and one new subspecies described and 2 poorly known species noted; new synonyms are indicated and distributions given.

Studies in Oxyanthus and Mitriostigma (Rubiaceae subfam. Cinchonoideae) for Part 2 of 'Flora of Tropical East Africa: Rubiaceae'

The species are dealt with in the order in which they will appear in Flora of Tropical East Africa with an additional species interpolated. Running numbers have been provided to facilitate the use of the index to epithets. Keys to infraspecific taxa are provided in instances where areas other than the Flora area are covered. Full citations are given for new species and short citations for new infraspecific taxa and in a few instances where the epithet dealt with has not previously been in common use. All specimens cited below have been seen unless otherwise stated; the geographical sequence follows F.T.E.A. usage. I wish to thank the Directors of the following Herbaria for sending me material on loan-Brussels (BR), Florence (FI) and Paris (P) and Dr Verdcourt for the latin translations and general advice.

A Revision of the Family Vahliaceae

All specimens cited below have been seen unless otherwise stated. I wish to thank the Directors of the following Herbaria for sending me material on loan: Berlin Dahlem (B), British Museum (Nat. Hist.) (BM), Coimbra (COI), East African Herbarium (EA), Lisbon (LISC), Lourengo Marques I.I.A.M. (LMA), Herb. Mus. Mogambique (LMM), Lourenqo Marques C.I.C.A. (LMU), Lund (LD), Pretoria (PRE), Salisbury (SRGH).

Additional notes on Coffea (Rubiaceae) from East tropical Africa

I hesitated to name Coffea sp. A. formally in Bridson 1982: 836 owing to lack of fruiting material and its rather close resemblance in general facies to C. pseudozanguebariae. Recently, fruiting material from specimens cultivated in the Ivory Coast has very kindly been sent to me by Mr J. Berthaud; these fruits differ from those of C. pseudozanguebariae. Furthermore, multivariate analyses carried out on populations of Coffea sp. A. and C. pseudozanguebariae by Hamon et al. (1984) (see also summary in Charrier & Berthaud 1985) give supplementary evidence to support the recognition of Coffea sp. A. as a distinct species.

Nichallea, a New Tropical African Genus in the Rubiaceae

Petit, in Bull. Jard. Bot. Brux. 31: 531 (1964), suggested that the systematic position of Tarenna soyauxii (Hiern) Bremek. needed re-examination. It was excluded from Tarenna by N. Halle in Fl. Gabon 17, Rubiacdes 2: 92 (1970) who indicated that a new genus in the tribe Coffeeae (Ixoreae) should be described to accommodate it. In my opinion T. soyauxii shows strong affinities to both Tarenna and Rutidea, but is not congeneric with either. I adopt Nicolas Halles suggestion and here formally describe a new genus and name it in his honour.