1184 CAKDUACEAE 



21. Chryaopaia atenophylla (A. Gray) Greene. Foliage finely hispid. Stemi 

 often tufted, 1-4 dm. tall, rigid, usually branched above : leaf-blades linear or linear- 

 spatulate, 2-4 cm. long, acute, entire, bristly ciliate near the base, sessile : heads showy : 

 involucres 7-8 mm. high ; bracts linear-subulate to narrowly linear, acute ; ray-flowers 

 with light yellow ligules 4-7 mm. long. 



In rocky soil or on sand hills, Nebraska to Arkansas and Texas. Summer and fall. 



22. Chryaopsia camporum Greene. Foliage hirsute. Stems 3-9 dm. tall, branched 

 above : leaves numerous ; blades oblong to linear-oblong, 3-7 cm. long, acute, sessile : 

 heads showy : involucres 9-1 2 mm. high ; bracts linear-subulate, acuminate, hirsute-strigose : 

 ray-flowers with deep yellow ligules 9-14 mm. long. 



On prairies, Illinois and Missouri, south to Kentucky and Arkansas. Summer. 



23. Chryaopaia Nuttallii Britton. Foliage villous or softly hirsute. Stems 3-8 dm. 

 tall, branching: leaves 1.5-4.5 cm. long; blades oblong to linear-oblong, entire or dis- 

 tantly toothed, acute, sessile, or the lower ones oblong-oblanceolate and commonly incised : 

 heads showy : involucres 8-10 mm. high ; bracts linear or linear-subulate, acuminate : ray- 

 flowers with ligules 1-1.5 cm. long : achenes 10-nerved. 



In open woods, Missouri and Kansas, south to Louisiana and Texas. Summer. 



26. X ANTHISMA DC. 



Annual or biennial caulescent herbs. Leaves alternate : blades narrow, entire. Heads 

 radiate, solitary at the ends of branches. Involucres campanulate to subglobose, many- 

 flowered : bracts closely imbricated, leathery at the base, herbaceous at the tip. Recep- 

 tacle flat. Flowers fertile. Corollas yellow. Stigmas tipped with filiform appendages. 

 Achenes turbinate, 4-5-ribbed or 4-5-angled, pubescent. Pappus of 10-12 main scales 

 prolonged into slender scabrous tips, usually accompanied by 10-12 shorter scales and an 

 external series of 5 still shorter scales, all persistent. 



Bracts of the involucre acute or acuminate : lower leaves with pinnatifid-toothed blades. 



1. X. Texanum. 

 Bracts of the involucre rounded : lower leaves with 1-2-pinnatifid or 1-2-pinnately parted blades. 



2. X. Berlandicri. 



1. Xantbiama Texanum DC. Stems 3-9 dm. tall, usually branched. Leaf-blades 

 narrowly oblanceolate to linear, 1.5-6 cm. long, acute, the lower ones pinnatifid-toothed, 

 the upper entire or nearly so : heads few, but showy : involucres about 1 cm. high ; bracts 

 elliptic, acute or acuminate : achenes 2 mm. long, pubescent. 



On prairies, Texas. Summer. 



2. Xanthiama Berlandieri (A. Gray) Small. Stems 2-4 dm. tall, sparingly 

 branched. Leaves numerous ; blades 1-6 cm. long, various, those below the branches 

 1-2-pinnatifid or 1-2-pinnately parted, the upper ones merely serrate or entire, appressed : 

 heads few, showy : involucres about 1 cm. high ; bracts oblong or oval, rounded. [X. 

 Texanum var. Berlandieri A. Gray. ] 



On plains, Texas. Spring and summer. 



27. CHONDROPHORA Raf. 



Perennial rigid caulescent herbs, often glutinous. Leaves alternate : blades narrow, 

 entire. Heads discoid, often in corymbs. Involucres narrow, few-flowered : bracts in 

 several series, firm. Receptacle flat, sometimes with teeth about the depressions. Corollas 

 yellow. Anthers obtuse at the base. Stigmas flattened. Achenes slightly flattened, 1-2- 

 ribbed on each side. Pappus of 1 or 2 scries of rigid hair-like bristles. 



Stem-leaves with linear or linear-spatulate blades. 1. C. nudata. 



Stem-leaves with filiform blades. 2. C. rinjuta. 



1. Chondrophora nudata (Michx. ) Britton. Stems 2-6 dm. tall, corymbosely 

 branched above. Leaves mainly basal ; blades spatulateto linear-spatulate or linear above, 

 3-12 cm. long, thickish, sparse on the stem : heads numerous : involucres nearly cylindric, 

 5-6 mm. high ; bracts oblong to linear, acute or acutish, the inner triangular at the apex : 

 achenes about 2 mm. long. [Bigelovia nudata (Michx.) DC.] 



In pine lands, New Jersey to Florida and Texas. Summer. 



2. Chondrophora virgata (Nutt. ) Greene. Similar to C. nudata. Stems corymbose 

 above, or sometimes thyrsoid : leaves mainly basal ; blades narrowly linear-spatulate or 

 filiform on the stem : involucres narrowly cylindric ; bracts lanceolate to linear, the inner 

 truncate and mucronate at the apex. [Bigelovia nudata var. virgata ( Nutt. ) T. & G. ] 



In sandy pine lands, North Carolina to Florida and Texas. Summer. 



