COMMELINACEAE 55 



2. LEMNA L. 



Frond 1-5-nerved. Flowers usually three together from a spathe, two 

 staniinate and one pistillate, the latter containing 7-12 ovules. 



Fronds stalked at base. 1. L. trisulca. 

 Fronds not stalked at base. 

 Fronds not symmetrical. 



Fronds 1-nerved. 2. L. cyiJodcisa. 



Fronds 3-nerved. 3. L. perpusiUa. 



Fronds symmetrical. 4. L. minor. 



1. L. trisulca L. Fronds oblong-lanceolate, 5'^-10^^ long, attenuate 

 at base into a slender stalk, denticulate at apex, thin, usually several 

 connected. — ^Common in pools at Shei3Seld, Lake City and Sibley. Summer. 



2. L. cyclostasa Phillippi. Frond elliptic-oblong, l'^-2^^ long, thick- 

 ish, obscurely 1-nerved. — Common in a pond near Slieffield and Courtney. 

 Summer. 



3. L. perpusilla Torr. Frond obovate, V^-\Y^ long, thickish, ob- 

 scurely 3-uerved, abruptly narrowed into a short stalk. — In ponds near 

 Courtney, Sheffield and Sibley. Summer. 



Var. trinervis Austin. Fronds strongly 3-nerved. — Ponds near Sheffield. 



4. L. minor L. Frond elliptic-obovate to suborbicular, l^^-2'^ long, 

 thickish, obscurely 3-nerved and never plainly stalked.— Often very 

 abundant in ponds at Sheffield, Sibley, Grain Valley and Lake City- 

 Summer. 



3. WOLFFIA Horkel. 



Fronds nerveless. Flowers two together, the one staminate, the other 

 pistillate. Ovule solitary. 



1. W. Columbiana Karst. Frond globose, y'-f/^ long, not dotted : 

 stomata 1-6. Floats just beneath tne surface of the water.- — ^In ponds 

 near Atherton, Sheffield and Lake City. June-July. 



Family 17. COMMELINACEAE Reichenb. 

 Herbs with perfect, 6-androus flowers subtended by spathe-like or leafy 

 bracts. Perianth double, the outer of three green sepals, the inner of three 

 ephemeral petals. Stamens 6. Ovary 2-3-celled, with 1-several ovules 

 in each cell. Style one. 



Two of the petals much larger than the third. 1. Commelina. 



Petals all similar. 2. Tkadescantia. 



1. COMMELINA L. Day Flower. 



Flowers subtended by a spathe-like bract. Sepals unequal, the two 

 lateral partly united. Petals blue, the two lateral on long claws, the 

 other smaller. Three stamens perfect, the other three sterile and smaller. 

 Filaments glabrous. 



1. C. ciispa Wooton. l°-3° high : leaves lanceolate, 3'-5^ long : 

 spathe cucullate : each cell of ovary 1-ovuled, the dorsal one indehiscent. — 



