23— NOTES ON SOME SOUTH AERICAN CYCADS. 

 By H. H. W. Pearson, M.A., F.L.S. 



(Abstract.) 



Field observations have been carried on in 1905 and 1906 on 

 Encefhalartos Friderici-Guilielmi, Lehm., E. Altensteinii, Lehm., 

 E. villosiis, Lem., and on the " open-veld " form of Stangeria, 

 which is possibly merely a variety of S. paradoxa, Moore. The full 

 paper (see Trans. S.A. Phil. Soc. , Vol xvi., pp. 341-354) contains a 

 discussion of the results obtained, the more important of which are 

 here summarized. 



In Encefhalartos Friderici-Guilielmi and in Stangeria sub- 

 terranean branching plays a part in vegetative reproduction which is 

 not less important thnn in many ferns with subterranean rhizomes. 



The cones are lateral in E. Friderici-Guilielmi and in E. Alten- 

 steinii, and the growth of the stem is in both cases monopodial. 



E. Friderici-Guilielmi, which is subject to strong insolation, 

 cones much more freely than either E. Altensteinii or E. villosus — 

 both, especially the latter, shade-species. 



In E. Altensteinii cones are not infrequent on plants growing in 

 more or less open positions exposed to sunlight. As far as is known, 

 they occur very rarely, if at all. on plants in densely-shaded situa- 

 tions. A few observations support a similar conclusion for E. 

 villosus. 



It may be that other exceptional circumstances, such as are 

 implied in cultivation, also act as a stimulus to the production of 

 cones. 



In E. Altensteinii branched specimens seem to occur only in 

 illuminated situations, and usually, if not always, near water — 

 conditions which are both favourable to nutrition. 



There is a distinct probability that entomophily occurs in 

 E. villosus. The position of the cones in Stangeria, with respect to 

 the surrounding vegetation, points to the inefficiency of the wind as. 

 a pollinating agent. 



