Oct> 20, 1927.] Revision of the Flora of Ihe Bombay Presidency 291 



sometimes reduced to the glumes or one glume only or quite suppressed. In- 

 volucral glumes permanently herbaceous, awnless like the hyaline 2-1-nerved 

 ciliate floral glumes. 



Accordingto Stapf (Fl. Trop. Afr., ix, 105) there are about 35 wild species 

 in the tropical and subtropical regions of both hemispheres, very few extending 

 into the temperate zones. One group of forms is widely cultivated in the tropics, 

 particularly in Africa. 



The classification of the material belonging to the section Eu-sorghum 

 forms a difficult problem, which we are not prepared to tackle at present. The 

 difficulties are well explained by Stapf (I.e.), and we cannot refrain from 

 quoting the passage, though somewhat length}', because it may be a help to 

 workers on this genus and induce them, at the same time, to subject the vast 

 material available in the Presidency to a more scientific examination and exact 

 taxonomic treatment, by which Botany as well as Agriculture will profit. 



Those species, says Stapf, 'which come under consideration in this work 

 (Flora of Tropical Africa) have with two exceptions (S. purpureo-sericeum and 

 5. versicolor) been placed by Hackel in one vast species, Andropogon 

 Sorghum, the leading idea being that they were all derived from one wild an- 

 cestor, the old Holms halepensis, Linn. Piper, however, has recently advan- 

 ced good reasons why this is extremely improbable. He has pointed out that 

 the Linnean Holcus halepensis {Andropogon Sorghum, subsp. halepensis, 

 var. genuinus, Hack.) is aperenn ; al type almost confined to the Mediterranean 

 region {sensu lato) and absent from tropical Africa which is the home of most of 

 the spontaneous annual forms and probably also the cradle of most of the 

 cultivated races known collectively as Guinea corn {Andropogon Sorghum, 

 subsp. sativus, Hack.) . To these spontaneous annuals and the cultivated forms 

 he confines the name Andropogon Sorghum, and dealing in particular with the 

 former he groups them under 11 subspecies, whilst he abstains from attempting 

 to classify the latter. Most of Piper's subspecies are here recognized as definite 

 units, but with the status of species, a procedure which seems to have the advan- 

 tage of simplicity and directness, whilst it leaves the door open to any theoreti- 

 cal grouping which may in the future be desirable. The same reasoning has 

 been applied to the cultivated forms. Hence the breaking up of Hackel's 

 Andropogon Sorghum, var. sativus. Koernicke, who made the first com- 

 prehensive attempt to classify them, relied for that purpose exclusively on 

 characters exhibited by mature infructescences, especially their degree of 

 looseness or contraction and the colours of the ripe glumes and grains ; but 

 Hackel in his monograph introduced characters taken from the shape of the 

 spikelets . The grain being in most cases the thing aimed at in the evolution of 

 these very numerous races, it is clear that artificially introduced modifications 

 must from the beginning have tended in the grain-state to obscure or repress 

 the phytogenetically important features in so far as they were economically 

 indifferent or undesirable. It seemed therefore, more promising to base the 

 primary grouping on the comparison of the flowering stages, which might be 

 expected to be more or less outside the influence of the artificially moulding 

 forces of man. Within these primary groups, which are treated here as species, 

 nothing more than a purely artificial arrangement can for the present be 

 attempted. An exhaustive treatment of the hundreds of races which have been 

 given distinctive popular names would, even if it were possible, be beyond the 

 scope of a colonial flora.' 



If Stapf, with all the facilities of Kew and the British Museum and other 

 European herbaria at his disposal, complains about * the very rudimentary state 

 of our knowledge and of our collections ' nobody can reasonably expect that 

 we should bring order into the chaotic state of the Sorghum question in India. 

 Years of intensive study of Indian and African forms are required to bring the 

 intricate problem nearer its solution. 



For the present we follow Haines in retaining the old species of 6". halepense 

 and 5. vulgure. Of species not known from the Presidency before we add 

 ►S. subglabrescens, Schweinf. & Aschers. and £\ nitidum, Pers. This, we 

 admit, is not quite satisfactory, but it is all we can offer at the present state of 

 our knowledge and with the material at our disposal in India. 



In order to enable Indian botanists to utilize Stapf 's and Piper's investiga- 

 tions in the further study of the genus Sorghum we shall add, in the way of an 

 appendix, the descriptions of those species which Stapf has described from 

 tropical Africa and which have also been observed in India, whether in the 



[ii] 



