28 



Dansk Botanisk Arkiv, Bd. 2. Nr. 6. 



Fig. 14 Cym. antarctica, from Henley 

 Beach, S. A. a, Female flower with in- 

 volucrum (/>) (about 2 /i n at. size), b, 

 Longitudinal section through the fruit 

 (about 3 / 2 nat. size), c, Ripe fruit with 

 "comb" and protruding plumula (about 

 3 / 4 nat. size). 



Through the kindness of Mr. Black I have secured a con- 

 siderable amount of herbarium material of Cym. antarctica from 



Henley Beach, S. A. and from it have been able to control his 

 description of the female flower and fruit, and its behaviour. 



The detached seedlings I found 

 myself on the West Austra- 

 lian coast, and also got some 

 from Mr. Hamilton from Bun- 

 burry; they seem to be com- 

 monly cast ashore during the 

 spring. At Carnarvon I hap- 

 pened to find a seedling which 

 was further developed and 

 showed the manner in which 

 the rhizome was formed (Fig. 

 12). By combining Mr. Black's 

 exhaustive description and 



my additional observations, we are able to give the following 



picture of the development of the propagation: 



The female flower consists of two carpels, as in the other 



species of Cymodocea; it is terminal at the apex of the upright 



branches, and is sheltered by two nearly 



opposite normal foliage leaves. All this 



is typical and was seen by Ascherson 



(1876), but in two points the flower differs 



from the ordinary Cymodocea flower: the 



styles of the carpels divide into three 



stigmas (not as usually into two), and the 



flower is enclosed in a membranous in- 



volucrum (Fig. 14 a); whether this cup is 



a kind of perianth or — more probably 



— bracteoles, I cannot say. According 



to Mr. Black this involucrum is well 



developed in his P. antarctica and nearly 



absent in his P. Griffithii. The flowers 



and fruits examined by me all had a more 



or less well-developed involucrum. 



After the fertilisation the carpels begin to grow, and espe- 

 cially four small outgrowths on their surface increase rapidly in 



size to form four flat cuneate spreading lobes. Inside them and more 



toward the apex of the carpel there are some smaller and more 



pointed protuberances which form a kind of protection around 



Fig. 15. Cym. antarctica, 

 from Henley Beach, S. A. 



a, An erect shoot with 

 leaves and the apical fruit. 



b, A seedling with its 

 "comb"-fruit cleft longi- 

 tudinally. ( 3 /4 nat. size.) 



