231 



Leaves usually oval or obovate, obtuse, four to six in a 



whorl. 2. H. tetraphylla. 



Very small Arctic plants, with linear, mucronate leaves, 



five to six in a whorl. 3. H. montana. 



1. H. vulgaris. L. Sp. PI. 4. (1753). 



Springing from a perennial rootstock, with annual, simple, 

 erect stems and whorls of six to twelve or more one-nerved linear 

 or lanceolate leaves which are more or less decayed (sphacelated) 

 at the tips, and 10-20 mm. long by 1-3 mm. broad. Stamens 

 with short, thick filaments and comparatively large two-celled 

 anthers, which dehisce laterally. Fruit oval, or somewhat four- 

 sided, hollow in the interior, 2 or 3 mm. long, stigmas persistent. 

 Common in Arctic America and Canada, It occurs also in Moose- 

 head Lake, Maine (Porter), west to Oregon, and thence to 

 California (Parish) and New Mexico. Mr. Safford sends it from 

 the Straits of Magellan, and it is common in Europe and Cen- 

 tral Asia, 

 Var. fluviatilis. Hart. Scand. Fl. 150 (1849). 



A very luxuriant, deep water form, entirely or nearly sub- 

 merged. Leaves 6 cn>: long by 2-3 mm. wide, grass-like, nu- 

 merous, in closely crowded whorls. Lake Winipeg (Macoun), 

 Keweenaw Peninsula, Michigan (Robbins) and Oregon (Lyall). 

 Not uncommon in Sweden. 



2. H. tetraphylla. L. f Supp. 81 (178I). 



H. lanceolata. Retz. Obs. Fasc. 3, 7, t. i (1783). 

 H. maritima. Hell. Dis. Hipp, in Ust. Opusc. L il. t. 

 I (1786). 

 This is usually a smaller plant than the preceding, rarely at- 

 taining a height of over 20 cm. Sometimes, however, as in 

 Labrador specimens, twice that height. The leaves are in whorls 

 of fours or sixes, oval, obovate or occasionally oblanceolate, but 

 little, if at all, decayed at the tips, and often feather- veined. Fruit 

 less than 2 mm. in length. It ranges from Alaska and Hudson's 

 Bay to the Gulf of St. Lawrence, and from Sweden to Siberia. 



3. H. montana. Ledeb. in Reich. Bot. i. 71 (1827). 



This diminutive northern plant, as Torrey and Gray remark, 

 (Fl. N. A. p. 531), looks very much like a small Galium. Stems 

 3-6 cm. high. Leaves one-nerved, linear, mucronate, in fives 



