Chrysocome^. composite. 191 



♦ Pappus of very short squameUale bristles. 



38. BRACHycHa:TA. Rays and disk-flowers each 4-5. Lower leaves cordate. 



* * Pappus of elongated capillary bristles. 



39. SoLiDAGO. Rays few, rarely none ; disk-flowers several. Receptacle alveolate. 



40. BiGELoviA. Rays none : disk-flowers 3-4. Receptacle cuspidate. 



41. LiNOSYRis. Rays none: disk-flowers 5-many. Receptacle alveolate-tootlied. 



Achenia oblong, silky-villous. 



42. Ammodia. Rays none : disk-flowers numerous. Scales of the involucre sca- 



rious-membranaceous. Achenia attenuate, hairy. 



43. Macronema. Rays 6-8, or none: disk-flnwcrs numerous. Scales of the in- 



volucre scarcely in two series, with foliaceous tips. Achenia flat, hairy. 



44. Ericameria. Rays3-(): disk-flowers 7-9. Scales of the oblong or cylindrical 



involucre imbricated. Achenia glabrous. Pappus copious. 



45. Stenotus. Rays 8-12 : disk-flowers numerous. Scales of the hemispherical 



involucre broad, closely imbricated. Achenia silky-villous. Pappus 

 copious, unequal. 



46. Isopappus. Rays 5-12: disk-flowers 10-20. Scales of the cylindrical involucre 



lanceolate-subulate. Achenia villous. Pappus equal, in a single series. 



* • * Pappus of nuTuerous uneqvM bristles, more or less rigid. 



47. Aplopappus. Achenia oblong or turbinate, villous or silky. Pappus of co- 



pious unequal and rather rigid persistent bristles. 



48. Pyrrocoma. Achenia linear, angled, glabrous. Pappus of copious uniform 



slender and rigid persistent bristles. 



49. Prionopsis. Achenia ovoid, glabrous. Pappus of very unequal deciduous 



bristles ; some of them very rigid. 



50. Centadridium. Achenia turbinate, pubescent. Pappus of several nearly defi- 



nite subulate persistent bristles. 



♦ * * * Pappus of few rigid awns or bristles. 



51. Grindelia. Pappus of 2-8 corneous caducous awns. 



52. PENTACHiETA. Pappus of 5 persistent rigid bristles. 



Subdiv. 4. HETEROTHECE.E. — Pappus of the ray and disk dissimilar. 



53. Bradburi A. Pappus of the ray double ; the exterior of short and squamellate, the 



interior of capillary barbellate bristles ; that of the disk of 2 chaffy awns. 



54. Heterotheceje. Pappus of the ray none ; of the disk as in Chrysopsis. 



Subdiv. 5. CHRYSOPSIDE.E. — Pappus of the ray and disk similar, double. 



55. Chrysopsis. Exterior pappus short, setose or chaffy ; the inner capillary. 



Subdiv. 1. Gymnosperme^, DC. — Pappus entirely wanting. 



35. GYMNOSPERMA. Less. syn. p. 194; DC.prodr. 5. p. 311. 



Heads 8-i4-flowered ; the ray-flowers 3-5 (sometimes wanting), very nar- 

 row, and with an extremely short ligule, pistillate ; those of the disk tubular 

 and perfect, sometimes sterile. Involucre oblong ; the scales imbricated, ap- 

 pressed, scarious-coriaceous. Receptacle narrow, naked. Corolla of the disk 

 with a cyathiform 5-cleft limb ; the lobes oblong-lanceolate, revolute. 

 Branches of the style oval or oblong ; the appendages as long as the stigmatic 



