PLATE 661. 



Ceratophtllum demehsum, Linn. (Fl. Br. India, Vol, V., p. 639.) 

 Natural Order, Ceratophxllb^. 



A submerged fragile slender herb. Stems reaching to 4 feet or more in length, 

 branching, the whole plant dark green. Leaves whorled, spreading when in the 

 water, collapsing in a tassel when removed, dichotomously cleft into linear, terete 

 lobes, the lobes distantly and sharply toothed in their upper portion, the whole 

 leaf clothed with minute cellular hairs, the teeth terminating in a transparent spine. 

 Flowers monoecious, axillary, solitary, minute. Male flowers solitary in axils, 

 perianth (or involucre), of 6-12 oblong segments which are irregular in shape, and 

 differing in the number of teeth from 2 to 6 ; all apiculate. Stamens numerous, 

 subsessile, anthers erect, 2-celled, connective produced beyond the anther-cells, 

 truncate, each cell furnished with 1 -2-projecting teeth on each side of the con- 

 nective. Female flowers solitary, perianth similar to that of the male flowers, 

 but narrower and longer, apiculus longer than in the male flowers. Ovary ovoid, 

 sessde, 1-celled, style subulate, flattened, stigmaticon one side; ovary solitary, pen- 

 dulous. Fruit an ovoid, coriaceous, compressed nut with a spongy outer covering, 

 an elongate persistent style, and a long linear-subulate appendage diverging from 

 the base on either side. 



Habitat : Natal : In a stagnant pool near Umgeni mouth. August, Wood 

 4000 (leaves and stems only^; same locality September, Wood 11713 (complete 

 specimens). 



The Order Ceratophylleae contains this one genus only. More than 30 species 

 have been described by authors, but all are now thought to be mere varieties of 

 the one species. In the Flora of British India three varieties are described, but 

 our species seems not quite to agree with any of them. 



These plants are said to be found in tanks and still waters in India, and also 

 in all temperate and tropical countries. It is quite possible that this plant is more 

 common in Natal than at present known to us, but we have met with it only in the 

 locality above quoted. 



Fig. 1 , male flower ; 2, perianth lobe ; 3 & 4, stamens ; 5, cross section of 

 anther; 6, female flower ; 7, perianth lobe of same; 8, pistil; 9, cross section of 

 ovary; 10, longitudinal section of same ; 11, capsule; 12, leaf; all enlarged. 



