8 ARKIV FOR BOTANIK. BAND 13. N:0 15. 



Vernonia Schreb. 



Key to the West Indian sections. 



I. Inner involucral scales with dilatated, membranaceous, 

 purplish-green tips. Bristles of the inner series of pappus 

 broad, flat, caducous. Tube 7 /s m length of the corolla. 



Sect. Stengelia. 

 II. Tips of the scales not dilatated. Bristles of the inner 

 series of pappus filiform or very inconspicuously flattened. 

 Tube not over 4 /s f the corolla. 



A. Inner scales caducous. Sect. Critoniopsis . 



B. Inner scales persistent. 



1. Inner bristles of pappus persistent. Achenes con- 

 spicuously 10-costate. Sect. Lepidaploa. 



2. Inner bristles caducous. Achenes faintly ribbed. 



Sect. Tephrodes. 



Sect. Stengel ia (Sch.-Bip.) Benth. 

 Yernonia anthelmintica (L.) Willd. 



Conyza anthelmintica Linnjeus, 1763, p. 1207. 

 Vernonia anthelmintica Willdenow, 1804, p. 1634. 



Pappi setae interiores caducae, numero circ. 30(?), fir- 

 mas, valde complanatae, pallide straminese, exterioribus late 

 linearibus circ. 8-plo longiores. Corolla glabra, 9 mm longa, 

 tubo gracili, superne subito dilatato, long. 7 /s corolla?, limbi 

 laciniis brevibus, apice papillosis. Antherae fere 2 mm longae, 

 ligula long. Vr, antherae, auriculis acutis. 



Hab. in Jamaica: Green Harbour, alt. 540 m, 13. 12. 

 94, Harris n. 5472 (BB, Br, KU, M). 



A well known, widely distributed species of the Old World, 

 introduced in Jamaica. 



Sect. Critoniopsis (Sch.-Bip.) Benth. 

 Yernonia tetrantha (Urb.) Ekman nov. comb. 



riptocarpha tetrantha Urban, 1899. p. 457; 1911, p. 620; Gleason. 

 1900 1), p. 160. 



Hab. in Porto Rico. 



