ECOLOGY AND TAXONOMY OF Holimeda 



151 



condition but felt that it occurred largely in stunted plants. She 

 assigned some of them to incrassata f. ovata. 



In addition to having this special nodal pattern, micronesica is 

 characterized by peripheral utricles which usually separate readily, and 

 by an extremely modified basal, rarely suprabasal, segment which may 

 become very large in some specimens but is less distinctive in others. 

 In well-developed plants the growth is prostrate, with branches 

 projecting in all lateral directions from the greatly enlarged basal 

 (suprabasal) segment. These branches occasionally terminate in rope- 

 like extensions to approximately 6 cm in length, which consist of 

 intertwined rhizoidal filaments. 



Halimeda fragilis W. R. Taylor 



Figure 47. 



Halimeda fragilis Taylor (1950), p. 88, Plate 48, Fig. 2; Hillis (1959), p. 363, 

 Plates 3, 5-9. 



Fig. 47. H. fragilis, with holdfast. From Enewetak Atoll, pass between Alembel and 

 Lojwa Islets, towards seaward side, 18 XII 75, Hillis-Colinvaux. Scale bar is 2 cm. 

 (Photograph by The Ohio State University Department of Photography.) 



Plants compact, often cushion-like, to 8 cm tall including the rather small 

 holdfast region, rhizoids not noticeably interlaced with sand particles; 

 calcification heavy; colour on drying white, cream or greyish-green, the 

 surface dull; branches occurring in more than one plane with up to four 

 arising from a single segment; basal segment generally inconspicuous, 

 cylindrical to reniform; others brittle, frequently ribbed and sometimes 



