FOUR-O'CLOCK FAMILY (NYCTAGINACEAE) 



Key to the 3 species illustrated (Xos. 31-33) 



A. Leaves thin or slightly thickened, rounded or short-pointed at both ends, hairy at least when young; fruits dry, 

 narrow, with 5 x-ows of rtotlike glands. 

 B. Leaves about half as broad as long, the lower surface densely Hne hairy — 31. Pisonia albida. 

 BB. Leaves nearly as broad as long, rusty bro^vn hairy when young but becoming hairless or nearly so — 32, 

 Pisonia subcordata. 

 AA. Leaves slightly thickened and succulent, short-pointed at both ends, hairless: fruits fleshy — 33. Torrubia fragrans. 



31. Corcho bobo 



This tree of dry areas is characterized by: (1) 

 brittle twio;s; (2) opposite elliptic leaves 2-6 

 inches lon<; and 1-3 inches broad, rounded or 

 short-pointed at both ends, the tipper surface 

 slightly shiny green and hairless, and the lower 

 surface paler and densely fine hairy; (3) many 

 flagrant small greenish flowers in terminal 

 branched clusters when leaves are shed or form- 

 ing; and (-i) numerous dark brown dry fruits % 

 inch long and I'le inch in diameter, the upper half 

 with 5 rows of raised glands and slightly sticky. 



A deciduous, usually small tree to 30 feet in 

 height and fi-1'2 inches in trunk diameter with 

 spreading crown, or shrubbj'. Base of trunk and 

 roots are often enlarged, suggesting an elephant's 

 foot with toes. The bark is whitish gray and 

 smooth. Inner bark is yellow or light brown, 

 gritty, and tasteless. Twigs are light green and 

 finely hairy, Ijecoming light gray. 



The leaves have finely hairy, pale yellow peti- 

 oles i/l~l^/4 inches long. The blades are thin or a 

 little thickened and not toothed on edges. 



Flowers are male and female on different trees 

 (dioecious) in terminal branched clusters (cymes) 

 on a stalk about 1 inch long. Male flowers are 

 short -stalked, consisting of greenish, finely hairy, 

 5-toothed bell -shaped calyx % inch long and usu- 

 ally 8 stamens about 1/4 inch long. Female flowers 



Pisonia albida (Heimerl) Britton 



in widelj' forking branched clusters have slender 

 stalks 1/^-1/4 inch or more in length; the greenish, 

 finely hairy, 5-toothed tubular calyx i ^ inch long, 

 and pistil with 1-celled, 1-ovuled ovary, style, and 

 stigma. 



Fruits (akenes) are numerous in a spreading 

 cluster of widely forking branches 2-3i/^ inches 

 long and broad, the whole cluster breaking off to- 

 gether. The tubular calyx remains outside of the 

 very narrow dark brown 1-seeded fruit. Flower- 

 ing when leafless or with new leaves, from Febru- 

 ary to May, and maturing fruits in late spring. 



The sapwood is yellowish or whitish. The heart- 

 wood is yellowish, coarse-textured, with silvery 

 gum in the pores, and moderately soft. T'sed only 

 as fuel wood in Puerto Eico. 



It is reported that the sticky fruit clusters fallen 

 on the ground can cause death of young chickens 

 that get tangled in them. 



In forests and thickets in the diy coast and lime- 

 stone regions of southern and western Puerto Rico. 

 Also common in Mona and in Caja de Muertos. 



PtTBLic FORESTS. — Guajataca, Guanica, Susiia. 



Range. — Hispauiola, Puerto Rico, Mona, and 

 Caja de Muertos. 



On IKK COMMON NAMES. — corclio blaiico, corcho 

 (Puerto Rico). 



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