CARDUACEAE. 193 



21. ACANTHOSPERMUM ychiank. Anmial coarse herbs. Leaves op- 

 posite: blades liroail, tootlieil. Heads inconspicuously radiate. Involucre 

 double: bracts of the inner series becoming bur-like, each one surrounding an 

 achene. Ligules of the ray-corollas concave or hooded, yellowish, inconspicuous. 

 Disk-corollas with the stamens borne high up on the tube. Pappus wanting. 



1. A. australe (L.) Kuntze. Stems branched at the base, the branches pros- 

 trate or creej)ing: leaf-blades ovate, oval, or rhombic, 1-2.5 cm. long: disk- 

 corollas about 2 mm. long: mature involucres starfish-like. — Pinelands and 

 waste grounds. Xat. of Trop. Am. 



22. BERLANDIERA DC. Herbs with woody tap-roots. Leaves alter- 

 nate, sometimes all basal: blades toothed or pinnatifid. Heads radiate, 

 solitary or corymbose. Involucre hemispheric or depressed, many-flowered: 

 bracts broad, in about 3 series, the inner thinner and more reticulate 

 than the outer. Ray-flowers 5-12, with yellow ligules. Disk-corollas with a 

 cylindric throat and a shorter tube ; lobes triangular or deltoid. Anthers 

 longer than the filaments. Aehenes flat, broadened upward, wingless, 1-ribbed, 

 adnate to the adjacent bracts of the involucre. Pappus obsolete or of 2 

 caducous awns. 



1. B. subacaulis Nutt. Stems 1-5 dm. tall, hispidulous: leaf -blades oblong to 

 oblanceolate, 4-12 cm. long, deeply sinuate-pinnatifid or lyrate-pinnatifid, the 

 lobes obtuse: bracts of the involucre oblong to oblong-spatulate, obovate or 

 cuneate, obtuse: ligules of the ray 1-1.5 cm. long: disk-corollas 3-3.5 mm. 

 long: aehenes obovate, 4-6 mm. long. — Pinelands. 



23. PARTHENIUM L. Coarse herbs, or shrubs. Leaves alternate: 

 blades toothed, xiinnatifid, or dissected. Heads inconspicuously radiate. In- 

 volucre depressed to globular: bracts appressed, broad. Ray-flowers usually 5: 

 ligules minute, white or whitish. Lobes of the disk-corollas ovate, ciliate. 

 Anthers longer than the filaments. Aehenes flattened. Pappus of 2 or 3 scales 

 or awns. 



1. P. Hysterophorus L. Plants annual, 3-7 dm. tall: leaf -blades oblong to 

 ovate in outline: involucres saucer-like, 4-5 mm. broad: disk-corollas 1-1.5 

 mm. long: aehenes 1-1.5 mm. long. — Pinelands and waste places. Nat. of 

 Trop. Am. — F. K. {Ber., Bah., Cuba, Ant.) 



24. VERBESINA L. Annual herbs. Leaves opposite: blades narrow, 

 entire or sparingly toothed. Heads small, inconspicuously radiate. Involucres 

 hemispheric or campanulate: bracts broad, those of the outer series scarcely 

 larger than those of the inner. Ray-flowers several : ligules white, incon- 

 spicuous. Disk-flowers several: corollas with a short tube and a longer funnel- 

 form throat : lobes deltoid. Anthers oblong, longer than the filaments, the 

 appendages ovate. Stigmas broad. Aehenes 3-4-angled, or somewhat flattened 

 in the disk. 



1. V. alba L. Stem and branches 2-9 dm. long, fleshy, finely pubescent : 

 leaf-blades elliptic, oblong or lanceolate, or narrower, .3-10 cm. long, sessile: 

 involucres broadly campanulate, the larger bracts about 4.5 mm. long: aehenes 

 about 2.5 mm. long.- — Everglades. — (Ber., Bah., Cuba, Ant.) 



25. MELANTHERA Rohr. Perennial herbs. Leaves opposite: blades 

 entire, toothed, or hastate-lobed. Heads tliscoid. Involucre hemispheric or 



>3 Flora of Miami 13 



