Studies in the Leguminosae-Papilionoideae for the 'Flora of Tropical East Africa': III

Abstract

A REAPPRAISAL OF THE SPECIES OF THE GENUS ABRUS ADANS. * Continued from Kew Bull. 24:' 70 (1970). All the material cited is in the Herbarium, Royal Botanic Gardens, Kew, unless otherwise stated. Specimens which have not been examined are indicated by an asterisk. A 235 236 KEW BULLETIN VOL. 24 specific limits had been drawn far too widely in this revision. During the preparation of an account of the genus for the 'Flora of Tropical East Africa', I reached the same conclusion and felt that the specific limits previously assigned were nearer the truth, and indeed, would have followed them had it not been for a need to comment on the revision mentioned. One of the primary practical functions of taxonomy is to give names to different plant populations so that their properties can be recorded, information tabulated and detailed phytogeographical studies made. Even if a species is genuinely polymorphic some grouping of the variants is still necessary if this primary aim is not to be lost sight of. Abrusfruticulosus sensu Breteler covers prostrate herbs, erect woody shrubs, plants with smooth pods, plants with densely tuberculate pods, plants with compressed unicolorous seeds and several Madagascan plants with spherical red and black seeds which are unquestionably much closer to Abrus precatorius L. but distinct. This aggregate contains many distinct species by any standards. Linnaeus would undoubtedly have separated most of the components. To sink wildly different components from areas thousands of miles apart which have not been seen in the field seems to me the height of folly and unlikely to serve any useful purpose. Since this present paper was first drafted Berhaut (in Adansonia 5: 359-362 (1965)) has commented on Breteler's paper and also described a further species. I have not attempted a complete revision since the main object was to find names for the East African entities. What appeared to be six clearly distinct entities in East Africa are treated as three in Breteler's revision so it became essential to look at the genus on a world basis. The following key is imperfect since full material is often not available. KEY TO THE SPECIES OF ABRUS Bracts and bracteoles very short or scarcely half as long as the calyx: Madagascan plants of which ripe pods and seeds are unknown (placed here since it is possible that these will prove to have seeds similar to those of A. precatorius) : Flowers (I-3-) I5-1 8 cm. long; leaflets about I-jugate, about 2 cm. long and I cm. wide. .. .. . I. A. grandiflorus Flowers smaller, not exceeding I-3 cm. in length: Leaflets 4-5-jugate, dark and glabrous above, the venation conspicuously pale, adpressed pilose beneath; inflorescences very short, about I cm. long. ..... 2. A. parvifolius Leaflets without conspicuous contrast between venation and rest of surface above and without other characters combined: Leaflets with fine adpressed greyish indumentum 3. A. diversifoliolatus Leaflets and rhachis with longer spreading or less adpressed greyish and ferruginous indumentum. 4. A. sambirane...

Ultrastructure of Dry Seed Tissue After a Non‐aqueous Primary Fixation

“…Unimbibed seed of mungbean, Vigna radiata (L.) Wilczek, formerly Phaseolus aureus (Verdcourt, 1970), were used in these studies. We also examined seeds of soybeans and red kidney beans, and although there were some differences in basic ultrastructure the quality of fixation was comparable in all three.…”

The origins and early dispersal of horsegram (Macrotyloma uniflorum), a major crop of ancient India

“…In addition, where seeds were visible on the herbarium specimen, or loose in attached pouches, these were measured. While Macrotyloma uniflorum occurs wild in Africa, and three subspecies have been described (Verdcourt 1970(Verdcourt , 1971, these have never apparently been domesticated. Therefore, their seed metrics provide a useful baseline for wild size range which augments the more limited materials of wild horsegram from India.…”

“…(Kingwell-Banham and Fuller 2014, 3490). Transferred from the heterogenous genus Dolichos to Macrotyloma in 1970 by the botanist Verdcourt (1970) (Smartt 1985, 298-299), horsegram is now in a genus that includes three economic plants: M. uniflorum, M. axillare (Meyer) Verdcourt (a fodder crop), and M. geocarpum (Harms) Maréchal & Baudet, the African groundbean or Bambara groundnut (Isely 1983, 492). Thus, Macrotyloma uniflorum (Lam.)…”

EFFECT OF ROOT, SHOOT AND RHIZOBIUM STRAIN ON NITROGEN FIXATION IN FOUR ASIATIC VIGNA SPECIES

“…However, grafting ^er se eflfectively delayed growth for 5 to 7 days. The absence of any obvious graft incompatibility among the Asiatic species is perhaps not surprising: all belong to the subgenus Ceratotropis (Verdcourt, 1970), and cytogenetic studies (Ahn and Hartman, 1976) suggest a substantial degree of chromosomal homology. Self-grafts were also readily achieved with cowpea, but all cross-grafts between cowpea (subgenus Vigna) and the Asiatic species were unsuccessful.…”