88 JUNCACEAE. 



Seeds not tailed. /. falcatus. 



Seeds tailed. J. regelii. 



Flowers bracteolate, loosely scattered or somewhat 

 congested but not in heads. 

 Annuals; stems branched, leafy. /. bufonius. 



Perennials; stems simple. 



Perianth segments 2.5-3 mm. long, obtuse. J. gerardi. 

 Perianth segments 3.5-5.5 mm. long, sharp- 

 pointed. 

 Auricle at summit of sheath, short and 



cartilaginous. /. dudleyi. 



Auricle at summit of sheath, elongated and 

 scarious. 

 Panicle loose; flowers pale green. J. tenuis. 



Panicle close; flowers fuscous. J. occidentalis. 



Leaves provided with distinct cross-partitions. 

 Blades of the leaves equitant. 



Heads pale, numerous; stamens 6. J. oxymeris. 



Heads brown or black; stamens 3, rarely 6. J", ensifolius. 



Blades of the leaves cylindric or only slightly com- 

 pressed. 

 Stamens 3. 



Plant aquatic, some of the leaves floating. J. supiniformis. 

 Plant not aquatic. 



Heads small, pale, several-many. J. acuminatus. 



Heads large, dark, few. J. bolanderi. 



Stamens 6. 



Capsules subulate; heads large; outer perianth 



segments longer. J. torreyi. 



Capsules not subulate. 



Heads solitary, dark. J. mertensianus. 



Heads several-many. 



Capsule much longer than the peri- 

 anth. /. oreganus. 

 Capsule shorter than the perianth. 



Perianth segments brown, acute. J. nevadensis. 

 Perianth segments pale, obtuse. /. alpinus. 



Juncus effusus L. Densely tufted, about 1 m. high, forming tussocks in 

 swamps; panicle compound, many-flowered; perianth-segments lanceolate, 

 acuminate, as long as the obovate obtuse capsules. 



A polymorphic species, of which three sub-species occur in our limits. 



Juncus effusus pacificus Fernald & Wiegand. Panicle loose; perianth- 

 segments pale, 2.5-3.5 mm. long. 



Everywhere common in wet ground. 



Juncus effusus hesperius Piper. Panicle compact; perianth segments 

 dark brown, 2.4-2.9 mm. long; upper sheath loose, membranous, dull, greenish- 

 drab above. 



Often occurring with /. effusus pacificus but blooming about a week 

 earlier; common near the seacoast. 



Juncus effusus gracilis Hook. Very similar to J. effusus hesperius but 

 upper sheath close, coriaceous, shiny, usually chestnut-colored. 

 In swamps, not common. 



Juncus balticus Willd. Stems erect, terete, naked, 30-60 cm. tall, from 

 stout horizontal rootstocks; leaves consisting only of sheaths; panicle appar- 



