soMi^: ()BS]£k\A rioNS Ox\ 'rHi<: occurrence of 



Hl'LBILS ON THE SUBTERRANEAN OR AERIAL 

 ORGANS OV PLANTS. 



Bv I'rof. Rldolf -Marlotii. M.A.. Ph.D. 



Plate II.) 



\'e,qetati\c reproduction by means of bulbilhe is known from 

 all classes of higher plants. It is of frequent occurrence among- 

 the bryophytes, and several genera of liverworts produce special 

 receptacles for their formation, e.g.. the common Mareha)ifia 

 poh.»morf>lia. Less frequent but not rare are bulbilliferous ferns, 

 e.g., Asplenium inonanihemum and A. gemmifentm. the " mother- 

 fern." 



There do not seem to be any bulbilliferous plants among 

 the Gymnosjjerms — at any rate, not in the South African flora. 



The best-known examples of bulbil-bearing Dicotyledons of 

 the British flora are Dent aria biilbifeya (Cruciferae) and Poly- 

 gonum viviparum (Polygonaceae). No bulbilliferous Crucifer?e 

 or Polygonaceae are known in South Africa. On the other hand, 

 we find a number of species of Oxalis bearing bulbillse, the 

 best-known example being O. eerniia, which under certain condi- 

 tions produces large numbers of bulbillas in its bulbs, as well as 

 in the axils of the leaves. As is usual with such plants, they 

 do not produce any seeds, although they may have flowered pro- 

 fusely. I have found plants of this species with a large number 

 of tiny bulbils, about the size of a cabbage seed, accimiulated in 

 the axils of the leaves. They are rich in starch, and eagerly 

 searched for by birds. On one occasion I found the crop of a. 

 pigeon almost filled with such bulbillae. 



C^f European Monocotyledons the best-known examples are 

 Llliitni bulbifentm (in the axils of the cauline leaves) and 

 AUium sativum (in the inflorescence), and of foreign plants 

 introduced into South Africa, Fourcroya gigantea (Amarylli- 

 dacese ) irova Central America, which bears numerous large, 

 green bulbils on the ramifications of the inflorescence. 



More numerous are such plants in our flora, producing them 

 on the subterranean as well as the aerial organs. 



I. On Subterranean Organs. 



We need not here consider the formation of several young- 

 bulbs by an older one, which process is of general occurrence 

 among Liliaceae and other orders, and for which the various 

 lilies, the onion, the Ornithogalum, etc., are familiar examples. 

 I wish to refer only to cases where the bulbilla? aj^pear in great 

 numbers around or within the princij)al bulb or corm. 



Albiica minor. — Several plants collected at Camps Bay in 

 October, 191 5, possessed numeroits small bulbils around the 

 parent bulb. Under ordinary circumstances the species readily 

 sets fruit, but when I gathered these two plants, one of which had 



