410 ALLIONIACEAE 



2. Boerhaavia linearifolia A. Gray. Perennial, slender, puberulent, hirsute and 

 more or less glandular. Stem diftusely branched at the base, the branches erect or ascend- 

 ing, 3-9 dm. long : leaf -blades linear to lanceolate, 1-3 cm. long, acute or acutish, usually 

 revolute, rounded or subcordate at the oblique base, short-petioled : peduncles slender : 

 calyx purple; tube glabrous or nearly so ; limb rotate, 12-14 mm. broad: stamens 5, ex- 

 serted : fruit oblong-clavate, 3 mm. long, 5-ribbed, rounded at the apex, glabrous. 



In arid places, Texas and New Mexico to Mexico. Spring and summer. 



3. Boerhaavia decumbens Vahl. Perennial, glabrous or nearly so. Stem branched 

 at the base, the branches decumbent, 4-11 dm. long: leaf-blades ovate, 2-4 cm. long, 

 rounded at the apex, strongly undulate, ciliate, whitisli beneath, rounded or subcordate at 

 the base ; petioles A as long as the blades or shorter : peduncles iiliform, loosely spreading : 

 calyx purple ; tube glandular ; limb carapanulate, nearly 1 mm. high, glabrous or nearly 

 so : stamens exserted : fruit club-shaped, about 3 mm. long, 5-angled, glandular-pilose, 

 obtuse at the apex. 



In dry soil, Florida to Texas, New Mexico and Mexico. Spring to fall. 



4. Boerhaavia hirsuta L. Annual or biennial, minutely pubescent and more or less 

 hirsute above. Stem branched at the base, the branches diffusely spreading, 6-12 dm. long : 

 leaf-blades ovate to oblong-ovate, 2-8 cm. long, acute or obtuse, and mucronate, ciliate, 

 undulate, both surfaces of almost the same color, the base rounded or truncate, or that of 

 the upper ones acute ; petioles i as long as the blades or shorter : peduncles wire-like : calyx 

 pink or purplish ; tube glandular-pubescent ; limb campanulate, l.o mm. high, glabrous or 

 sparingly pubescent : stamens exserted : fruit obpyramidal, 3 mm. long, the ribs glandular, 

 the top rounded. 



In dry soil, peninsular Florida and southern Texas to Mexico. Also in tropical America. Spring 

 to fall. 



5. Boerhaavia viscosa Lag. & Rodr. Annual or biennial, stout, with viscid pilose 

 hairs or puberulent. Stem widely branched at the base and tliroughout, the branches 

 spreading in all directions : leaf -blades ovate to oblong, 2-4 cm. long, obtuse or mucronate, 

 or acute, undulate, rounded or obtuse at the base, wliitish beneath, becoming glabrous; 

 petioles ^ as long as the blades or shorter : peduncles slender : calyx pink or purple-pink, 

 glandular; limb campanulate, 1-1.5 mm. long: stamens 3, exserted: fruit club-.shaped, 

 3-3.5 mm. long, acutish. 



In sandy soil, peninsular Florida. Also in tropical America. Summer and fall. 



6. Boerhaavia er6cta L. Annual or perennial, roughish pubescent or glabrous. 

 Stem simple below, erect or ascending, or branched at the base, the branches decumbent or 

 spreading, 3-12 dm. long: leaf-blades ovate to deltoid-ovate, sometimes inequilateral, 2-8 

 cm. long, acute or obtuse and apiculate, repand or undulate, varying from acute to cordate 

 at the base, minutely black-dotted on the lower whitish surface ; petioles usually about i as 

 long as the blades or longer : peduncles filiform : flowers 2-6 in a cluster : calyx white to 

 purple; tube glabrous ; limb campanulate, 1-1.5 mm. long, sparingly pubescent : stamens 

 exserted : fruit obpyramidal, 3.5-4 mm. long, 5-angled, the grooves transversely wrinkled, 

 the top flat. 



In dry soil. South Carolina to Texas, south to Florida and Mexico. Also in tropical America. 

 Spring to fall. 



8. PISONIA L. 



Tropical shrubs or trees, with erect or partly climbing armed or unarmed stems. 

 Leaves opposite or alternate, without stipules : blades entire. Flowers perfect, dioecious 

 or rarely monoecious, small, green or yellow, in pedunculate compound cymes : 

 pedicels bracteolate, subtended by small bractlets. Calyx campanulate, tubular or funnel- 

 form, accrescent : limb 5-lobed or 5-toothed, erect or spreading. Stamens 5-30, usually 

 5-8, inserted on the base of the calyx or under the ovary : filaments filiform, distinct or 

 united at the base, exserted, unequal : anthers introrse. Style stoutish, terminal or nearly 

 so : stigma capitate, radiate or fimbriate. Fruit angled or ribbed, sometimes with rows 

 of glands. 



Fruit with 5 rows of glands. 



Plant spiny: leaf-blades acute or short acuminate : fruit glandular from the base to the apex. 



1. P. aculeata. 



Plant unarmed : leaf-blades blunt or retuse : fruit glandular above the middle. 2. P. rutundata. 

 Fruit without glands. 



Leaf-blades glabrous : fruit not constricted under the apex. 3. P. obtmata. 



Leaf-blades copiously pubescent : fruit constricted under the apex. 4. P. Floridana. 



1. Pisonia aculeita L. A shrub, 1-2 m. tall, with widely spreading branches, 

 spine-armed. Leaf-blades elliptic, oval or ovate, 2.5-5 cm. long, acute or short acumi- 



