DOGBANE FAMILY (APOCYNACEAE) 



219. Palo amargo, bitter-ash 



This small tree or shrub with white latex is dis- 

 tinguished by its shiny yellow-green lance-sliaped 

 or narrowly elliptic leaves 21/4-6 inches long and 

 %-l% inches wide, long-pointed at apex and base, 

 slightly turned under at edges, attached to the 

 twig in groups of 4 of unequal size (whorled). 

 The small whitish flowers are about 14 'n^b across 

 and the reddish to blackish rounded fruits about 

 % inch long and I4"y2 inch broad. 



Commonly a shrub or small tree to 20-40 feet 

 high and to I14 feet in trunk diameter, evergreen 

 with open rounded crown. The bark is smoothish, 

 slightly fissured and warty, very light brown, and 

 thin. Inner bark is light green and bitter. The 

 twigs are bright green with raised brown dots 

 (lenticels), enlarged at the nodes, and becoming 

 brownish. 



The slightly thickened leathery leaves have 

 petioles 14-% inch long and blades green or yel- 

 low green on upper surface and lighter yellow 

 green beneath. 



The small flower clusters (cymes) are terminal 

 or lateral, branched, 1-1 V2 inches long and broad, 

 shorter than the leaves, with several to many flow- 

 ers. The white and greenish flowers are tubular, 

 about % inch long, with 5 spreading lobes 14 inch 

 across ; the green 5-lobed calyx is less than i/g inch 

 long; corolla has a narrow greenish tube 14 inch 

 long and 5 rounded white lobes; 5 minute stamens 

 are inserted near mouth of corolla tube; and the 

 pistil is composed of a 2-lobed ovary with slender 

 style and enlarged stigma. 



The fleshy fruits, with milky juice, turn from 

 green to reddish and blackish and contain 1 or 2 

 brownish seeds %6 inch long. Flowering and 

 fruiting nearly throughout the year. 



RauvolHa nitida Jacq. 



The sapwood is light brown, and the heartwood 

 clear yellow. The hard, lightweight wood is em- 

 ployed for posts in Puerto Rico. Elsewhere, use 

 for furniture and musical instruments has been 

 suggested. 



In the coastal and limestone forests and thickets 

 of Puerto Rico, growing in the open and probably 

 requiring light. Also in Mona, Vieques, St. Croix, 

 St. Thomas, St. John, and Tortola. 



Public forests. — Cambalache, Guanica. 



Range. — Bahamas, Cuba, Jamaica, Hispaniola, 

 Puerto Rico and Virgin Islands, St. Kitts, Guade- 

 loupe, and Martinique. Also recorded long ago 

 from St. Barthelemy. 



Other common names. — palo de muneco, ca- 

 chimbo (Puerto Rico) ; bitterbush, milkbush (Vir- 

 gin Islands); palo de leche (Dominican Repub- 

 lic) ; huevo de gallo (Cuba) ; smooth rauvolfia 

 (Bahamas) ; bois lait femelle (Haiti). 



The name of a low shrub {Ruuvolf-a tetraphylla 

 L.) has been misapplied to this species. 



The genus Rait vol fia (also spelled Raitwolfia) 

 has attracted much attention in recent years be- 

 cause the root of a shrubby species in India has 

 yielded a drug for the treatment of high blood 

 pressure and certain mental illnesses. Related spe- 

 cies are also under investigation. 



Another native species is a shrub 3-10 feet high 

 known as bitterbush {Rauvolfia vindis Roem. & 

 Schult.; synonym R. lamarckii A. DC). It has 

 slightly unequal leaves in groups of 4 (whorled), 

 ovate to elliptic, mostly 11/2"^ inches long, thin, 

 dull green instead of shiny, and smaller blackish 

 fruits about 14 inch broad. It gi-ows in coastal 

 thickets of eastern Puerto Rico, Mona, Icacos, 

 Culebra, Vieques, St. Croix, St. Thomas, St. John, 

 and Virgin Gorda and other islands to Hispaniola 

 and northern South America. 



4(A 



