The present revision deals with the morphology, taxonomy, and geography of Allium,
indigenous or cultivated, on the continent of Africa. Many data on ecology, anatomy, and other botanical disciplines, either compiled from the herbarium labels, from observations in the field or in the garden, or from literature, are added.
All species are amply illustrated, often in much and varied detail.
For Africa the full synonymy is given, as well as type-specimens, a full description, distribution, and notes on various other aspects of the taxa.
The arrangement of
the species is not alphabetically, but according to the recognized sections, and hence to a certain degree systematically. Thus, besides the key to the species and the descriptions, the illustrations will strongly facilitate the identification of
of Africa are largely confined to the northern, mainly Mediterranean region; one species, A. dregeanum,
presumably indigenous there, is recognized for southern Africa.
In total 27 wild species are accepted for Africa; in addition four of
the more commonly cultivated species are treated, together 31 species. Several species are subdivided into subspecies. Contrary to previous authors the African species have been amply compared with, or studied in conjunction with related or identical species from the nearby Mediterranean areas in southern Europe and the Near East, which forced me ultimately to accept a rather wide species-concept, often leading to extensive synonymy, including many names formerly proposed for Europe.
In this revision no new names are proposed; only A. subhirsutum
L. ssp. sub-villosum
(SCHULTES) DUYFJES, A. subhirsutum
L. ssp. spathaceum
(A. RICHARD) DUYFJES, A.sphaerocephalum
L. ssp. durandoi
(BATTANDIER et TRABUT) DUYFJES, and A.sphaerocephalum
L. ssp. curtum
(BOISSIER et GAILLARDOT) DUYFJES are proposed under a new status or combination.
The 31 African species are subdivided into 6 sections. These are defined as far as the African species are concerned, but the accepted sections are used in the sense of previous authors working on Allium
outside Africa, e.g. STEARN, WENDELBO, and others. It appeared that a final subdivision into sections should await an overall treatment of
this large genus of
500-600 species, which is mainly and almost exclusively distributed on the whole northern hemisphere.
Short introductory essays deal with various general aspects, such as morphology, seedlings, anatomy, palynology, caryology.
All citations to authors refer to an extensive separate bibliography.
The work concludes with an index accounting for supposedly all names, specific and infraspecific, for Africa, with in addition many names of related species or synonyms from adjacent areas, mainly Europe.
A separate article on the typification of Linnean Allium
species likely to occur in Africa, is added to the thesis.