390 COMPOSITAE. 



lanceolate, sessile, pinnately lobed or parted; heads in a rather dense cyme; 

 involucre hemispheric; tcgules linear-lanceolate, acute, 8-10 mm. long; ray- 

 flowers 12-15. 



In talus at the base of cliffs. Mount Adams, Suksdorf, Howell; Mount 

 Rainier in Indian Henry Park, Tarleton. 



540. PSILOCARPHUS. 



Low woolly annuals; leaves entire, mostly opposite; heads 

 small, discoid, many-flowered, in terminal capitate clusters and 

 in the forks of the branches, surrounded by the upper leaves; 

 fertile flowers numerous, in several series on the globular chaffy 

 receptacle; pappus none; akene loose in the bladder-like bract, 

 oblong or narrower, slightl^^ compressed. 



Heads covered with long loose woolly hairs. P. elatior. 

 Heads covered with short close wool. 



Prostrate; leaves oblong or elliptic. P. tenellus. 



Ascending; leaves narrowly oblanceolate. P. oreganus. 



Psilocarphus elatior Gray. Erect and simple or more commonly branched 

 from the base and spreading, 5-10 cm. high, loosely white-woolly throughout; 

 leaves lanceolate or linear-spatulate, 1-2 cm. long; heads 6—8 mm. broad, 

 subtended by leaves; fruiting tegules appressed, tomentose; akcnes cylindrical. 



In low ground, especially in dried-up ponds, Vancouver Island to Idaho 

 and Oregon. First found near Portland, Oregon. 



Psilocarphus tenellus Nutt. Canescently tomentose wdth fine appressed 

 wool; stems ascending, much branched from the base, 3-8 cm. high; leaves 

 spatulate, 5-10 mm. long; heads small, numerous, in fruit 4-6 mm. in diameter; 

 akenes fusiform, oblong, 1 mm. long. 



Vancouver Island, Macotin; Fairhaven, Whatcom County, Washington, 

 Suksdorf; not otherwise known north of California. 



Psilocarphus oreganus Nutt. Stems ascending, 2-5 cm. high; leaves 

 narrowly oblanceolate, 8-10 mm. long; heads covered with close wool; bracts 

 2 mm. long; akenes cylindric. 



The original specimens were collected by Nuttall " near the Oregon and 

 outlet of the Wahlamet." The plant has not since been found west of the 

 Cascade Mountains, but it is not rare in the interior. 



541. ANTENNARIA. 



Low white-woolly cespitose perennials; leaves alternate, entire; 

 heads small, solitary or corymbose, completely dioecious; re- 

 ceptacle naked ; staminate flowers with the pappus-bristles thick- 

 ened or barbellate at the apex; pistillate with the slender pappus- 

 bristles united at base into a ring. 



Plants not stoloniferous; stems 5-10 cm. high. A. lanata. 



Plants stoloniferous, growing in patches; stems usually 15 or 

 more cm. high. 

 Heads loosely racemose; inflorescence glandular. A. racemosa. 



Heads corymbose; inflorescence not glandular. 



Leaves 3-5 cm. long, oblanceolate or narrowly obovate. 



Green and glabrate above. A. howellii. 



Tomentose on both surfaces. A. concolor. 



