POLYGONACEAE (BUCKWHEAT FAMILY) 



Var. hastata (Nutt.) Duchartre. Leaves narrow, lanceolate or linear- 

 oblong, sagittate or auriculate-hastate. (A. hastata Nutt. ; A. Nashii Kearney.) 

 S. 0. to Fla. and La. ; said to reach our southern limit in Va. 



* * Calyx-tube strongly curved like a Dutch pipe, contracted at the mouth, the 



short limb obscurely 3-lobed ; very tall twining shrubs. 



2. A. macrophylla Lam. (PIPE VINE, DUTCHMAN'S PIPE.) Nearly gla- 

 brous; leaves round-kidney-shaped (sometimes 4 dm. broad); peduncles with a 

 clasping bract ; calyx (3 cm. long) with a brown-purple abrupt flat border. (A. 

 Sipho L'He>.) Rich woods, Pa. to Ga., w. to Minn, and Kan. May. 



3. A. toment6sa Sims. Downy or soft-hairy; leaves round-heart-shaped, 

 very veiny (8-16 cm. long) ; calyx yellowish with an oblique dark purple closed 

 orifice and a rugose reflexed limb. Rich woods, N. C. to Fla., w. to s. 111. and 

 Mo. June. 



* * * Calyx-tube straight, open, with ample 6-lobed limb, the lobes appendaged; 



anthers equidistant; erect herbs ; flowers in axillary cymose fascicles. 



4. A. CLEMAT!TIS L., with long-petioled cordate leaves, sometimes cultivated, 

 has become locally established in the Atlantic States from N. Y. to Md. (Introd. 

 from Eu.) , 



POLYGONACEAE (BUCKWHEAT FAMILY) 



Herbs, with alternate entire leaves, and stipules in the form of sheaths (ocreae, 

 these sometimes obsolete) above the swollen joints of the stem; the flowers mostly 

 perfect, with a more or less persistent calyx, a l-celled ovary bearing 2 or 3 styles 

 or stigmas, and a single erect orthotropous seed. Fruit usually an achene, com- 

 pressed or 3-4-angled or -winged. Stamens 4-12, inserted on the base of the 

 3-6-cleft calyx. 



* Flowers involucrate ; stamens 9 ; stipules none. 



1. Briogonum. Involucre several-flowered, with flowers exserted. Calyx 6-cleft. 



* * Flowers without Involucre ; stamens 4 to 8. 



-i- Stipular sheaths manifest ; ovule erect from the base of the cell. 



++ Sepals 4 or 6, the outer row reflexed, the inner erect and enlarging in fruit. 



2. Oxyria. Sepals 4. Stigmas 2. Achene orbicular-winged. Leaves reniform. 



3. Rumex. Sepals 6. Stigmas 3. Achene 3-augled. 



++ ++ Sepals 5 (sometimes 4), equal and erect in fruit ; achene triangular or lenticular. 



4. Polygonum. Embryo slender, curved around one side of the albumen. Achenes inclosed by 



the somewhat enlarged fruiting calyx (or exserted in a few species with lanceolate or 

 linear leaves). 



5. Fagopymm. Embryo in the albumen, its very broad cotyledons twisted-plaited. Fruit much 



exserted from the scarcely enlarged calyx. Leaves deltoid, sagittate or hastate. 



6. Polygonella. Embryo slender, nearly straight Pedicels solitary. Leaves linear. Plant 



heath-like. 



i- +- Stipules obsolete ; ovule hanging from the apex of a slender stalk. 



7. Brunnichia. Calyx 5-parted, in fruit with a wing decnrrent on the pedicel. Tendril-climber. 



1. ERI6GONUM Michx. 



Flowers perfect, involucrate ; involucre 4-8-toothed or -lobed, usually many- 

 flowered ; the more or less exserted pedicels intermixed with narrow scarious 

 bracts. Calyx 6-parted or -cleft, colored, persistent about the achene. Stamens 

 9, upon the base of the calyx. Styles 3 ; stigmas capitate. Achene triangular. 

 Embryo straight and axial, with foliaceous cotyledons. Leaves entire, without 

 stipules. (Name from tpiov, wool, and y6w, knee.} 



1. E. longifblium Nutt. Perennial, erect ; leaves oblanceolate, acute or 

 acutish, canescent beneath, the lower cuneate at base; sepals linear, caudate- 



BRAY'S MANUAL 23 



