Parr 3, 1918] ALLIONIACEAE 187 
Staminate flowers dark-red, in compact head-like cymes 1-2.2 
em. broad. 
Leaf-blades acute or acutish, obovate or oblong-obovate, 
nearly glabrous; spines straight. 5. P. flavescens. 
Leaf-blades rounded or obtuse at the apex, orbicular or 
rounded-obovate, densely pubescent on both surfaces; 
spines usually recurved. 6. P. capitata. 
Plants unarmed. 
Leaf-blades herbaceous, acute to acuminate at the base; staminate 
flowers in a head-like cyme. 7. P. Donnell-Smithii. 
Leaf-blades coriaceous, obtuse to subcordate at the base; staminate 
inflorescence not head-like, 
Petioles 2-9 mm. long. 8. P. rotundata. 
Petioles 11-30 mm. Jong. 
Leaf-blades usually 2.2-6.5 em. broad, obtuse or rounded at the 
base, pubescent beneath; fruit 5-angled. 9. P. albida. 
Leaf-blades mostly 5-9 cm. broad, usually subcordate at base, 
glabrous or nearly so; fruit terete, 10-costate. 10. P. subcordata. 
1. Pisonia Helleri Standley, sp. nov. 
Branches stout, dark reddish-brown, with few lenticels, armed with numerous stout 
recurved spines 4-10 mm. long, the branchlets glabrous or sparsely puberulent; petioles 
slender, 0.4-3.5 cm. long, glabrous; leaf-blades oval-elliptic, oblong-elliptic, ovate-oblong, or 
oval, 3.5-8.5 cm. long, 1.5-4.5 cm. wide, acute to attenuate at the base or rarely rounded, 
gradually or abruptly acute to attenuate at the apex, thick and succulent, deep-green, glabrous, 
the margins plane, the lateral veins usually nearly obsolete; peduncles of the staminate in- 
florescence 1-2.5 cm. long, stout, puberulent or short-villous, the cymes densely or loosely 
flowered, 2-4 cm. broad, the flowers yellowish-green, numerous, on pedicels 0.5-2 mm. long, 
the bractlets ovate or oblong, 1 mm. long, obtuse, densely puberulent, the perianth broadly 
campanulate, 2.5-3 mm. long, densely puberulent, the lobes deltoid, acutish: stamens 6 or 7, 
twice as long as the periantb; peduncles of the pistillate inflorescence 2—3 cm. long, slightly 
elongate in age, the cymes at first dense and only 1.5-2 cm. broad, in fruit 8-12 em. broad, 
the pedicels at anthesis 0.5-2 mm. long, in age 1-3 cm. long, the perianth 2 mm. long, the tube 
short and stout, the limb ascending or spreading, the lobes broad, obtuse; fruit clavate or 
clavate-oblong, 10-14 mm. long, 5-6.5 mm. in diameter, rounded or slightly depressed at the 
apex, woody, 5-angled, the angles furnished with a row of low pluriseriate glands, the faces 
densely puberulent; seed cylindric, acute at the base, about 1 cm. long and 2-3 mm. in diameter, 
dark-brown, striate. 
Type collected two miles west of Bayamon, Porto Rico, April 29, 1899, Mr. & Mrs. A.A. Heller 
1245 (U.S. Nat. Herb. no. 426204). . j 
DIsTRIBUTION: Porto Rico, Jamaica, Hispaniola, Martinique, Guadeloupe, and Antigua. 
2. Pisonia macranthocarpa Donn. Smith, Bot. Gaz. 20: 293. 1895. 
Pisonia nigricans Griseb. Fl. Brit. W. Ind. 70, in part. 1859. Not P. nigricans Sw. 1800. 
Pisonia aculeata macranthocarpa Donn, Smith, Bot. Gaz. 16: 198. 1891. 
Pisonia aculeata pedicellaris Griseb.; Heimerl, Bot. Jahrb. 21: 633. 1896. 
Shrub or small tree, the branches stout, dark reddish-brown, with numerous conspicuous 
lenticels, the branchlets stout, puberulent when young but soon glabrate; spines few, often 
wanting on the ultimate branches, usually straight, stout, 5-8 mm. long; petioles stout or 
slender, 0.5-2.5 cm long; leaf-blades elliptic to broadly oval or rarely broadly obovate, often 
irregular in outline, acute to attenuate at the base, acute to attenvate at the apex, sometimes 
abruptly so, or rarely obtuse or rounded, coriaceous, deep-green, concolorous, glabrous on 
the upper surface, puberulent or short-villous beneath along the costa, or sometimes glabrate 
in age, the margins plane, the lateral veins evident, ascending at an angle of 45-60°; peduncles 
of the staminate inflorescence 1.5--3 cm. long, viscid-puberulent or hirtellous, the cymes dense, 
many-flowered, 2- 3.5 cm. broad, the flowers short-pedicellate, the bractlets ovate, acute, 1 mm. 
long, puberulent, the perianth broadly campanulate, 3-4 mm. broad, yellowish-green, rubert- 
lent, the teeth short, deltoid, acute; stamens usually 8, twice as long as the perianth; peduncles 
of the pistillate inflorescence at anthesis 1-2 cm. long, 4-8 cm. Jong in fruit, the cymes many- 
flowered, divaricately branched, at anthesis 2-3 cm. broad, in age 5-12 cm. broad, the branches 
puberulent, the bractlets oblong or linear, about 1 mm. long, the pedicels at anthesis 1-2 mm. 
