240 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 



J. acuminatus Michx. — Wet meadows and along brooks; occa- 

 sional. Lenox; Otis; New Marlboro; Sheffield. 



J. articulatus L. — Low ground, roadside ditches, borders of 

 brooks and ponds; common. Altitude 1500 feet, Greylock. 



var. obtusatus Engelm. — Wet meadows and hillside brooks; 

 occasional in the valley. Lanesboro; Pittsfield; Great Harrington; 

 Sheffield. 



J. brachycephalus (Engelm.) Buchenau. — Bogs, wet meadows, 

 marshy or muddy shores; frequent. Summit of Greylock, 3500 feet. 



J. brevicaudatus (Engelm.) Fernald. — Wet ground; common. 



J. bufonius L. — Wet roadsides and muddy shores; common, 

 particularly on the plateau. 



J. canadensis J. Gay. — Open bogs and marshes; common. 



J. Dudley! Wiegand. — Moist sandy or gravelly ground, low 

 meadows and roadside ditches; common in calcareous soil in the 

 valley, reaching an altitude of 1300 feet in Tyringham. 



Key to Juncus effusus. 

 {Vid. Rhodora, 12: 83-84.) 



A. Flowers small, sepals 1.7 to 2.6 (rarely 2.9) mm. long, mostly somewhat 



spreading from the base; perianth segments not very dark but usually 

 with two distinct brown lateral bands, rather soft in texture and there- 

 fore not rigid when dry; inflorescence small (1 to 4 cm. in diameter), 

 or if larger with the sepals less than 2.6 mm. long. 



Culms rather stout, 1.5 to 4 mm. in diameter at the top of the 



sheaths; sheaths pale; inflorescence small, compact. 

 Culms finely many-striate and usually deep green . . var. compactus. 

 Culms coarsely 12- to 15-sulcate, usually pale green. 



var. conglomeratus. 



Culms rather slender, 1 to 2 (rarely 3) mm. in diameter at the top 



of the sheaths; sheaths dark; inflorescence small and rather 



close var. dedpiens. 



B. Flowers medium or large, sepals 2.5 to 4.2 mm. long (rarely shorter); 



perianth segments with no conspicuous brown bands, frequently firmer 

 in texture, often rigid, appressed or somewhat spreading; inflorescence 

 commonly open, rarely somewhat dense, 1.5 to 14 cm. in diameter. 

 Sepals rarely exceeding either the petals or the capsule, 2.5 to 3.5 mm. 

 long, firm, not conspicuously spreading nor strongly contrasting in 

 color with the capsule. 



Culms 2 to 4.5 mm. in diameter at the top of the sheaths, not 

 sulcate var. solutus. 



