384 ASTERACEAE. 



Involucre campanulate, Its bracts imbricated in 3-4 

 series, the inner somewhat scarious and striate. Recep- 

 tacle chaffy; the chaffy bracts persistent, lanceolate, 

 partly embracing the achenes, nearly equaling those of 

 the involucre. Corollas tubular, yellow. Achenes tur- 

 binate, slightly obcompressed. Pappus consisting of 1 

 series of long rather stout plumose bristles. 



1. B. juncea (Benth.) Greene. Much branched from a woody 

 base, 10-15 dm. high; flowering branches rush-like, nearly leafless, 

 pale green and glabrous or minutely and sparsely scabrous; leaves 

 mainly opposite, linear; heads scattered, terminating the branchlets, 

 1 cm. high; pappus-bristles equaling the slender corollas; achenes 

 appressed-pubescent. 



Occasional in dry washes. Santiago Canyon, Santa Ana Moun- 

 tains, Geis; Highlands. 



Tribe 6. MADIEAE. Tarweed Tribe. 

 Annual or perennial herbs, with usually glandular 

 viscid or heavy-scented herbage. Leaves alternate or 

 opposite. Involucral bracts in 1 series, each partly or 

 wholly enclosing an achene. Bracts of the receptacle 

 commonly in a single series between ray- and disk- 

 flowers. Rays always present and fertile, destitute of 

 pappus. Disk-flowers sterile or fertile, their pappus 

 paleaceous, awn-like or none. 



Ray-achenes laterally compressed, completely 

 enfolded by the involucral bract. 

 Rays inconspicuous. 



Disk-flowers several. 36, Madia. 



Disk-flowers 1-4. 41. Harpaecarpus. 



Rays showy. 37. Madaria. 



Ray-achenes somewhat obcompressed, half 

 enclosed by the bracts. 

 Leaves spiny; flowers yellow. Z^. Centromadia. 



Leaves not spiny. 



Herbage somewhat glandular; flowers 



yellow. 39. Deinandra. 



Herbage not glandular; flowers white or 



rose color. 40. Calycadenia. 



Ray-achenes obcompressed or clavate, com- 

 pletely enfolded by their bracts. 

 Bracts 5; herbage canescent. 42. Lagophylla. 



Bracts more than 5. 



Rays showy, yellow or white. 43. Layia. 



Rays inconspicuous; pappus becoming 

 showy. 44. Achyrach,(Ena. 



