CARDUACEAE. 151 



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: achenes 1-1.5 mm. long. Pinelands and waste places. Key "West. 

 Nat. of Trop. Am. [E. K.] (Ber., Bah., Cuba, Ant.) 



15. MELANTHERA Bohr. Perennial herbs. Leaves opposite: blades 

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

 depressed: bracts often broad, in 2 or 3 series. Throat of the corolla much 

 longer than the tube. Filaments generally as long as the black-tipped anthers 

 or nearly so. Stigmas stout or flattened. 



Bractlets of the receptacle long-acuminate, like the bracts of the 



involucre, coarsely pubescent. 1. M. parvifolia. 



Bractlets of the receptacle acute or short-acuminate, like the 



bracts of the involucre, finely puberulent. 2. M. brevifolia. 



1. M. parvifolia Small. Stems 3-8 dm. tall, very rough-hispidulous, slender, 

 sparingly branched: leaf-blades prominently hastate, 2-5 cm. long, or longer, 

 the lateral lobes prominent, coarsely toothed or entire, the middle lobe elongate, 

 contracted between the lateral lobes and the dilated apex, usually coarsely 

 toothed above, the petioles rather short: heads few, usually very long- 

 peduncled: larger bracts of the involucre 5-7 mm. long. Pinelands and 

 coastal sand-dunes, U. S. keys, U. keys, L. keys. [E. K.] 



2. M. brevifolia O. E. Schulz. Stems 8-24 dm. tall, somewhat rough-pubes- 

 cent, often stout, considerably branched: leaf -blades ovate to deltoid or ovate- 

 hastate or deltoid-hastate, 8-15 cm. long, obtuse or acute, usually crenate, the 

 petioles rather long: heads several or numerous, mostly rather short-peduncled : 

 larger bracts of the involucre 3.5-5 cm. long. Hammocks and coastal sand- 

 dunes, U. S. keys, U. keys, L. keys, L. S. keys. [E. K.](Bah., Cuba.) 



16. BORBICHIA Adans. Fleshy maritime herbs or shrubs. Leaves oppo- 

 site: blades thick, entire, or toothed. Heads erect, on stiff peduncles. Invo- 

 lucre hemispheric or flattish: bracts fleshy or leathery. Kay-flowers few. 

 Disk-corollas with a cylindrie-funnelform throat and a very short tube: lobea 

 eciliate. Free portions of the filaments much longer than the corolla-tube. 

 Pappus crown-like. SEA OX-EYE. 



Outer bracts of the involucre spreading or reflexed at maturity : bractlets of the 

 receptacle spine-tipped. 1. B. frutescens. 



Outer bracts of the involucre appressed at maturity : bractlets 



of the receptacle obtuse or barely mucronate. 2. B. artorescens. 



1. B. frutescens (L.) DC. Plants 2-7 dm. tall: leaf -blades linear- spatulate 

 to obovate, 2-6 cm. long: outer bracts of the involucre acute, the inner ones 

 subulate-tipped. Shores and sand-dunes, U. S. keys, U. keys, L. keys. [E. K.] 

 (Ber.) 



2. B. arborescens (L.) DC. Plants 2-12 dm. tall: leaf -blades oblanceolate or 

 spatulate-oblanceolate, 3-6 cm. long: outer bracts of the involucre acute, the 

 inner ones rounded at the apex. Shores and sand-dunes, U. S. keys, U. keys, 

 L. keys, L. S. keys. [E. K.] (Ber., Bah., Cuba, Ant.) 



17. HELDLNTHUS L. Erect or creeping herbs. Leaves alternate or 

 opposite: blades entire or toothed. Heads solitary or clustered. Involucre 

 campanulate, cylindrie, or depressed: bracts various, often narrow, sometimes 

 elongate. Kay-flowers few or many, or rarely wanting. Disk-corollas with a 

 cylindrie throat and a very short tube: lobes eciliate. Free portions of the 

 filaments much longer than the corolla-tube. Pappus of 2 awns or scales which 

 are sometimes accompanied by smaller ones. 



