192 COMPOSITE. 



of receptacle mostly in a single row between ray and disk, and often 

 united into a cup. Disk-corollas usually hairy. Style-branches subulate, 

 hispid. 



* Involucral bracts quite enclosing eachiits r ay-ache ne. 



Achenes compressed, /. e., flattened laterally MADIA 38 



obcompressed; 



Rays very short, erect; pappus showy ACHYRACH^ENA 43 



" broad, spreading; pappus none LAOOPHYLLA 44 



; ampler; 



Pappus of ray short, cup-like; of disk scanty HOLOZONIA 45 



" " none; of disk copious BLEPHARIPAPPUS 46 



* * Involucral bracts half enclosing their achenes. 



Receptacle chaffy throughout; leaf -lobes pungent CENTBOMADIA 40 



leaves not pungent HEMIZONIA 39 



Receptacle chaffy only between disk and ray; 



Rays few (often 1 only); plants with large saucer-shaped 



glands CALYCADENIA 41 



RaysSor more ^ papt>U8 P^ mo8e BLEPHARIZONIA 42 



paleaceous or HKMIZONIA 39 



38. MADIA, Molina (TARWEED). Glandular and viscid heavy-scented 

 herbs, with at least the upper leaves alternate, entire, or merely toothed. 

 Heads axillary and terminal, the yellow flowers vespertine, closing in 

 sunshine. Involucre angled by the salient carinate backs of the uniserial 

 involucral bracts; these completely enfolding the laterally compressed 

 smooth achene, and having free herbaceous tips. Eeceptacle flat or 

 convex, bearing a single series of chaff united and forming a cup which 

 separates between rays and disk-flowers. Ligules 3-lobed. Bracts of 

 involucre deciduous with the mature achenes (except in n. 2); these 

 smooth, beakless, (except in n. 7). 



* Annuals; rays short, inconspicuous; pappus none. 



1. M. sativa, Mol. Stout, 1 4 ft. high, pubescent with slender 

 hairs and beset with pedicellate very viscid glands, ill-scented: leaves 

 lanceolate, nearly entire: heads ^ in. high, short peduncled or sessile in 

 the upper axils and at the ends of some short branches : cup of receptacle 

 broadly campanulate, enclosing many disk-achenes, these cuneate oblong 

 and 4- angled; ray-achenes falcate-obovate. By waysides and in culti- 

 vated lands. July Sept. 



2. M. capitata, Nutt. Size of the last, but more expressly viscid 

 herbage honey-scented, the loose hairs hispid: leaves linear, sessile by a 

 broad base: heads longer and narrower, capitate congested at the ends 

 of stout ascending short branches : involucre very hispid : cup of receptacle 

 narrow and nearly closed, the achenes within it very few: ripe involucral 

 bracts and achenes semipersistent. Marin Co., and far northward. 

 Very distinct; early-flowering. April June. 



