498 coMPosiTxE. (composite family.) 



52. CHAEDINIA. Unarmed herbs, with entire leaves, and scarious involucre, all the 



scales appressed, silvery-white. 



53. SIEBERA. Herbs with aspect of 51 and 52, but the inner scales of involucre spiny in 



fruit. 



54. CARLINA. (2) Ij! Leaves and involucre spiny, the inner rows of involucre radiating. 



55. ATRACTYLIS. 2f Leaves and involucre spiny, the latter double, the inner rows 



of inner involucre not radiating. 



SoBTRiBE III. CARDXJINEiE. Akenes glabrous (except StcBhelina), the hilum 

 at base straight or oblique. Pappus bristly or slightly chaffy at base, caducous or 0. 



* Filaments free, glabrous, or hairy. Bristles of pappus separate, equal. 



56. LAPPA. (D Unarmed herbs, the scales of the involucre tipped with a hook. 



57. COUSmiA. 2|! (D SpIny herbs. 



* * Filaments free, papillose-hairy , or glabrescent. Pappus united in a ring at base, equal. 



58. CAEDUUS. (g) Prickly herbs. Pappus scabrous, Eeceplacle fringed. 



59. CIESIUM. (D If Prickly herbs. Pappus plumose. Eeceptacle fringed. 



60. NOTOBASIS. Prickly herbs. Pappus plumose. Eeceptacle linear-paleaceous. 

 6L CHAMJEPEUCE. ^ Unarmed shrubs, with linear-filiform leaves. Pappus plumose. 



62. ONOPOEDON. (5) Prickly herbs, with large heads. Tip of anther subulate. 



63. CTNAEA. 2|! P^ckly herbs, with large heads. Tip of anther obtuse. Pappus plumose. 



* * * Filaments united in a sheath, glabrous, hirsute at base, or papillose. Pappus equal. 



64. SILYBUM. @ Spiny herbs, with large heads. Scales of involucre prickly at margin 



and tip. 



65. TYEIMNUS. Soft-prickly herbs, with small heads. Scales of involucre prickly only 



at tip. 



* * * * Filaments free, glabrous. Pappus unequal. 

 •j- Pappus nearly in 1 row, sometimes with a few, small bristles outside. 



66. ST^HELINA. ^ Unarmed herbs, with lanceolate to linear leaves and oblong- 



cylindrical heads, 

 j f Pappus ofaa rows, gradually increasing in length from without inward. 



67. JUEINEA. 2C 5 Leaves undivided. Scales of involucre prickly-mucronate or -tipped. 



Pappus caducous. 



SuBTRiBE IV. CENTAURE.iE. Akenes usually glabrous, hilum oblique or lateral. 

 Pappus chaffy, bristly, or 0. 



* Heads naked at base (except a few Centaur eoe, and Cnicus). 



68. SEEEATULA. 2L Unarmed. Stem-leaves undivided or pinnatisect. Heads discoid, 



oblong-ovate to oblong, .02 to .04 long. 



69. CEUPINA. Unarmed. Leaves 1-2-pinnatiparted. Heads discoid, oblong,. few-flowered, 



.01 to .02 long. 



70. AMBEEBOA. Unarmed. Leaves pinnatisect. Heads rayed, ovate, few-flowered, 



.01 long. 



71. ZOEGEA. Unarmed. Heads radiate, rays saffron-colored to white, .03 to .04 



broad ; tip of akene concentrically grooved. 



72. CENTAUEEA. If 5 Unarmed or spiny herbs, rarely shrubs. Pappus of two sorts, 



the outer of several rows of bristles or pales, the inner of 1 row 

 of short, connivent pales. 



73. CNICUS. Low. Leaves sinuate-pinnatifid. Heads large. Scales of involucre tipped 



with a pinnate spine. 



