Fig. 76: Halophila Engelmannii: a, habit, X %; b, young leaf, X 1. (Courtesy of 

 R. K. Godfrey). 



6. Halophila Thou, 



Several species widespread in marine waters of tropical and warm temperate 

 regions. 



1. Halophila Engelmannii Asch. Fig. 76. 



Submersed perennial with horizontal slender creeping scaly branching stoloni- 

 ferous stems 1-1.5 mm. thick that root at the nodes and produce short erect 

 leafy branches; internodes 2-4 cm. long; scales and leaves in pairs, opposite; 

 scales broadly obovate, glabrous, to about 1 cm. long; erect shoots 2-4 cm. long, 

 with 1 pair of scales at the middle and 2 or 3 pairs of leaves clustered at the 

 summit; leaves sessile or with a very short thick petiole 2 mm. long or less, linear- 

 oblong to oblong-elliptic, obtuse to subacute at apex, tapering at base, to 4 cm. 

 long and 8 mm. wide, rather thick, faintly 3-ribbed and with 6 to 8 pairs of lateral 

 veins, reticulate-roughened, finely serrulate on the margins; flowers 1 or 2 enclosed 

 in a bifoliate sheath, both kinds often in the same sheath; pistillate flowers sessile 

 in the axils of the leaves; hypanthium ovoid, 3-4 mm. long, its neck about 5 mm. 



168 



