C. H. Ostenfeld: Contributions to West Australian Botany. I. 



41 



As in other species of Halophila, there is a transversally 

 creeping, thin and fragile rhizome On its younger parts two 

 membranous and early deciduous amplexicaul scale-leaves are 

 present at each node, from which an erect assimilative shoot and 

 an unbranched root arise. The assimilative shoots attain to 17 — 

 18 cm in length, and bear numerous pairs of foliage leaves. These 



Fig. 25. Halophila spinulosa, from Carnarvon. A Flowering male plant with 

 creeping rhizome and erect assimilative shoots. The flowers are hidden in 

 the upper parts of some of the assimilative shoots. (Photo, of herbarium 



material). 



leaves are opposite and distichous, and are turned in such a 

 manner that they stand edgewise; therefore the whole shoot is 

 quite flat. Such a distichous arrangement of opposite leaves is 

 rare, though there is a somewhat similar arrangement in Pota- 

 mogeton densus and in Euphorbia buxijolia (civ. E. Warming, in 

 Bull. Acad. Roy. sc. et lettr. de Danemark, pour l'année 1896). 



