Everlasting Tribe 407 



20. PLUCHEA Cass. 



Herbs or shrubs with alternate leaves and small heads 

 of tubular flowers in terminal cymose clusters. Involu- 

 cral bracts imbricated in several series, appressed, her- 

 baceous. Receptacle flat. Outer flowers of the head pis- 

 tillate, their corollas filiform, 3-cleft or dentate. Central 

 flowers perfect, but mostly sterile, their corollas 5-cleft. 

 Achenes small, 4-5-angled or sulcate. Pappus a series 

 of capillary scabrous bristles. 



1. P. sericea (Nutt.) Coville. (ARROWWOOD.) Shrub, 4 in. 

 high or less, with suberect slender willowy branches, very leafy 

 up to the cymose clusters of rather small heads; leaves silky- 

 pubescent, 2.5-5 cm. long, linear-lanceolate, acute at both ends, 

 entire ; involucre campanulate ; outer bracts ovate, obtuse, tomen- 

 tose; inner ones narrowly linear, deciduous; flowers whitish, 

 tinged with purple or red ; pappus copious, the bristles of the 

 sterile flowers clavellate-dilated, of the fertile slender. (P. borealis 

 Gray.) 



Rather common along the streams, especially in the interior valleys, 

 May-July. 



2. P. camphorata DC. Annual, stoutish, minutely and some- 

 what viscid-pubescent, leafy, 6 dm. high; leaves oblong-ovate to 

 oblong-lanceolate, acute at both ends, toothed or denticulate, the 

 larger 7-12 cm. long, petioled ; heads short-pedicelled, dull purple, 

 crowded in a corymbose cluster; bracts ovate to lanceolate, often 

 colored. 



Occasional along streams and marshes about Los Angeles; Ballona 

 Creek. 



21. MICROPUS L. 



Low floccose annuals with alternate entire leaves and 

 several-flowered scattered heads. Pistillate flowers in 1 

 or 2 series on a small receptacle, each enclosed in a con- 

 duplicate bract which has a scarious, appendiculate lip. 

 Hermaphrodite sterile flowers central, few, mostly naked. 

 Involucre outside of the fruiting bracts scanty and 

 scarious. Achenes gibbous, obovate, each enclosed in its 

 bract and falling away with it. Pappus none. 



