310 Gleason: Studies on West Indian Vernonieae 



Vernonia gnaphaliifolia Rich, in Sagra, Hist. Fis. Pol. Nat. 



Cuba ii : 34. 1850 

 Vernonia sublanata Gleason, Bull. N. Y. Bot. Gard. 4: 177. 1906. 

 Dr. Urban has established the identity of these two species by 

 the examination of authentic material, and they are accordingly 

 united here. The species appears to be common and widely 

 distributed in Cuba from the province of Havana eastward. 



Species-group Divaricatae 



The history of this group of Vernonieae begins with the 

 publication of V. divaricata by Swartz in 1806. This was followed 

 in 1 83 1 by Lessing's V. acuminata, and no further addition was 

 made to the group until 1906, when Gleason described V. albicoma 

 and V. expansa. During the last half-century V. divaricata and 

 V. acuminata have been usually considered identical. The whole 

 group, so far as known, is confined to Jamaica, and the ample 

 collection in the Herbarium of the New York Botanical Garden 

 includes seven distinct species. 



At the present time the chief difficulty lies in determining to 

 which of these seven species the old names divaricata and acuminata 

 belong. Certain characters given by the authors in their original 

 descriptions serve to exclude one or another of the species, and 

 by this process of exclusion it is possible to arrive finally at a 

 reasonable conclusion. It may be safely affirmed that the two 

 species described below are the only ones examined to which 

 these names can consistently be given, without doing violence to 

 some important feature of the original description. 



Vernonia divaricata Sw. Fl. Ind. Occ. 3: 1319. 1806 



A straggling shrub, 1-2 m. high; leaves spreading, thin, bright 

 green, elliptical or elliptical-lanceolate, 4-7 cm. long, 1.5-2.5 cm. 

 wide, acute or subacuminate, entire, narrowed to an acute base, 

 minutely puberulent above, thinly pubescent and finely punctate 

 with minute pellucid glands beneath, sessile or with petioles 1-5 

 mm. long; inflorescence of numerous, lax, loosely flowered, di- 

 varicate cymes, bearing each 5-15 secund heads, and frequently 

 prolonged into a leafy shoot; bracteal leaves oblanceolate to 

 narrowly oblong, barely exceeding the 11-13-flowered heads; in- 

 volucre campanulate, about 4 mm. high; scales thinly strigose- 



