16 



Dansk Botanisk Arkiv, Bd. 2. No. 6. 



8 mm lang, bei jenen nur 3), letztere zeigen auch eine gestrecktere 

 Form, indem sie als halbelliptisch (jene halboval) zu bezeichnen 

 sind". Later, the male flower has been found as may be seen 

 from Ascherson (1907) in „Das Pflanzenreich" (IV, 11; 149) where 

 the anthers of C. isoetifolia are given as 2 mm long. Here the 

 diagnosis of C. manatorum consists only of the following words: 

 "A praecedente o: [C. isoetifolia] differt: Folia longiora graciliora 

 in sicco nigricantia. Flores quam in praecedente plus duplo 

 majores, sed iis C. nodosae minores". 



The flowering material of C. isoetifolia from Carnarvon gave 

 an opportunity for a more detailed study of the differences be- 

 tween the two species, as I had also ample material of C. mana- 

 torum from the Danish 

 West-Indies, collected by 

 E. Warming and myself. 



As to the length of the 

 leaves of C. isoetifolia, the 

 Geraldton specimens show 

 that it varies from 20 — 30 

 cm (including the sheaths 

 which are 3 — 4 cm) ; in the 

 Carnarvon specimens the 

 leaves are 12 — 15 cm long 

 with sheaths 2 — 2,5 cm long. 

 Specimens in the Botanical 

 Museum of Copenhagen 

 from the Red Sea and from 

 Ceylon have the leaves 

 nearly as long as those 

 from Geraldton, while, according to Ascherson (1907) the leaves 

 reach only 15 cm, i. e. only the half of what I have actually 

 measured. The leaves of numerous specimens of C. manatorum 

 from the West Indies attain to 32 cm at the most, with sheaths 

 4 — 4,5 cm long. Therefore, as regards length of leaves there is 

 no difference between the two species ; the same is the case with 

 their colour. 



Sauvageau (1890, pp. 188 — 191) has studied the anatomy of 

 the leaves of the two species. On the whole they are much 

 alike, but there is a well-marked difference in the number of veins. 

 In C. manatorum there are only two "lateral" veins besides the 

 central one, while in C. isoetifolia the "lateral" veins, which are 



Fig. 4. Cymodocea isoetifolia from Carnarvon. 



a A male inflorescence, b A male flower. 



c Part of a female inflorescence, (a and c, 



nat. size; b, 3:1 nat. size.) 



