143 



Roots one or more. Flowers inserted on margin of 



fronds. Anthers 2-celled. Lemna. 



Rootless. Flowers bursting from surface of frond. 



Anthers 1-celled. Wolffia. 



1 Lemna, Lhm. 



minor, Linn. 

 gibba, „ 



List of Species. 



2 Wolffia, Horhel. 

 A-B. Michellii, Schleid. 



ORDER CXCV. NAIDACE^. 



X smaU family of aquatic or marsh herbs, none of which are of 

 any special value to mankind. The species of Triglochin are said to 

 be all marsh herbs, but we have found T. bulbosum growing on dry 

 hills, and in crevices of rocks far from water or marsh}^ ground. 



Number of species about 120. 



KEY TO GENERA. 



Stigmas discoid or decurrent on the ovary. 

 Stigfmas subulate or capillary. 



1 Perianth of sepals or scales. Flowers bisexual. 



1 Perianth none. Flowers unisexual. 

 2 Marsh herbs. Sepals 6, green 

 2 Aquatics. Sepals 1-3, white or coloured. 

 2 Aquatics. Sepals 4, herbaceous, green. 



3 Aquatics. Stamen I Carpels usually sessile. 

 4 Aquatics. Flowers sessile, on a flat linear spadix. 



Trtglochin. 

 Aponogeton. 

 potamogeton. 

 Zannichellia. 



ZOSTERA. 



1 Triglochin, Linn. 



bulbosum, Linn. 

 laxiflorum, Guss. 

 striatum, Ruiz ^ Pav, 



2 Aponogeton, Thh. 



natalense, Oliver, 

 spathaceum, Hook. 



3 Zannichellia, Mich. 

 palustris, Liim. 



List of Species. 



4 Potamogeton, Linn. 



americanus, Gham. 

 crispum, Lin7i. 

 Friesii, Buprecht, 

 javanicus, HassJc. 

 lucens, Linn. 

 natans, „ 

 pusillus, L. 



5 Zostera, Linn. 

 nana. Both. 



B-E. 

 A. 

 A. 



C-E. 

 A-E. 



A. 

 AB, 



A. 



C. 

 A-B. 

 A-B. 

 A-B. 



A. 



ORDER CXCVI. ERIOCAULEiE. 



A family containing 6 genera, only one of which is represented 

 in Natal, by 7 named species of marsh herbs, none of which are of any 

 economic value, the leaves are usually rosulate, and under the micro- 

 scope are seen to be septate. 



