300 ARROWHEAD ORDER 



1. Flowers perfect; leaves not arrow-shaped ALISMA 



2. Flowers monoecious or dioecious ; leaves arrow- 



shaped SAGITTARIA 



ALISMA Linne 1753 WATER PLANTAIN 

 (Name of uncertain origin and meaning) 



Sepals 3, green, petals 3, white or rose-tinted, stamens 6-9, pistils usu- 

 ally 12-18, achenes flattened, curved and ribbed; flowers many in panicle- 

 like clusters ; leaves erect or floating, ovajte to lance-linear ; perennial. 

 Flower-stalks 1-4 ft. high; leaves ovate to elliptic; 



flowers 5-7 mm. wide A.plantago-aqudtica 



SAGITTARIA Linne 1753 ARROWHEAD 



(Lat. sagitta, arrow, from the shape of the leaf) 



PI. 44, fig. 2. 



Sepals 3, green, petals 3, white, stamens usually numerous, pistils 

 numerous, achenes flattened in rounded heads ; flowers monoecious or dioe- 

 cious, in whorls of 3's, staminate usually above ; leaves basal, arrow-shaped, 

 or the blade lost ; aquatic or marsh perennial. 



1. Basal lobes of the leaf lance-linear, forming % to 



y^ the length of the whole leaf 5". longiloba 



2. Basal lobes more or less triangular and broad, 



forming % to ^ the length of the whole leaf 



a. Beak of the achene more than % its length S. latifolia 



b. Beak of the achene less than y\ its length S. arifolia 



TYPHACEAE CAT-TAIL FAMILY 



Sepals none, and petals reduced to bristles, stamens 2-7, filaments united, 

 pistil 1, stalked, ovary 1-2-celled, styles 1-2, bristly hairs among the stamens 

 and pistils ; flowers monoecious in dense terminal spikes, staminate spike 

 above the pistillate ; marsh or aquatic plants with creeping root-stocks and 

 erect cylindric stems and long-linear, flat, sword-like leaves, sheathing at 

 the base. 



TYPHA Linne 1753 CAT-TAIL 



(The Greek name) 

 Characters of the family. 



1. Leaves 6-12 mm. wide; spikes dark brown to 

 black, often 1 in. or more wide, the pistillate 

 and staminate parts usually touching; stigmas 

 spatulate or rhomboid T. latifolia 



