Genus 8. 



BUCKWHEAT FAMILY. 



671 



8. BISTORTA Adans. Fam. PI. 2 : 277. 1763. 



Perennial herbs with corm-like scaly rootstocks. Stems erect, simple. Leaves alternate, 

 mostly basal, narrow or sqmetimes rather broad, continuous with the ocreae. Ocreae elon- 

 gated, oblique at the top,- persistent. Flower-clusters contiguous, dense. Raceme oblong 

 or cylindric, solitary, sometimes with bulblets replacing the lower flower-clusters. Calyx 

 white or pale. Sepals 5, slightly enlarged but otherwise unchanged at maturity. Stamens 

 5-8, exserted; filaments very slender. Styles 3, slender, exserted, nearly straight; stigmas 

 capitate. Achenes 3-angled, loosely included in the calyx. [Latin, double-twisted, refer- 

 ring to the shape of the rootstock.] 



About 8 species, natives of boreal regions. Besides the following, two or more others occur 

 in western North America. Type species : Polygonum Bistorta L. 



i. Bistorta vivipara (L.) S. F. Gray. Alpine Bistort. Serpent-grass. Fig. 1645. 



Polygonum viviparum L. Sp. PI. 360. 1753. 



Bistorta vivipara S. F. Gray, Nat. Arr. Brit. PI. 2 : 268. 

 1821. 



Perennial, mostly glabrous and somewhat glau- 

 cous ; stems solitary or clustered, erect, simple, 

 slender, 2'-io' tall. Basal leaves oblong or lanceo- 

 late, 1 '-8' long, rather acute at the apex, cordate or 

 subcordate at the base, long-petioled ; stem leaves 

 narrowly lanceolate or linear, i's' long, the lower 

 petioled, the upper sessile, their margins often revo- 

 lute: ocreae long, clasping below, open above; ra- 

 ceme solitary, terminal, narrow, rather dense, bear- 

 ing a number of dark colored bulblets about its 

 base; calyx 5-parted, pale rose-color or white; 

 stamens 8, exserted; style 3-parted, its branches 

 exserted; achene oblong, 3-angled. 



Greenland and Labrador to Alaska, south to the high 

 summits of the mountains of New England, in the 

 Rocky Mountains to Colorado and to Washington. Also 

 in arctic and alpine Europe and Asia. June-Aug. 



9. FAGOPYRUM Gaertn. Fr. & Sem. 2 : T82. 1791. 



Annual or perennial rather fleshy, usually glabrous leafy herbs, with erect, simple or 

 branched, striate or grooved stems. Leaves alternate, petioled, hastate or deltoid, with 

 oblique, cylindric or funnelform ocreae. Flowers small, white or green, in terminal or 

 axillary usually paniculate racemes, perfect, borne solitary or several together from each 

 ocreola, slender-pedicelled. Calyx about equally 5-parfed, persistent and unchanged in fruit, 

 the segments petaloid, shorter than the achene. Stamens 8, included; filaments filiform, 

 glabrous; anthers oblong. Ovary i-celled, i-ovuled; style 3-parted; stigmas capitate. 

 Achene 3-angled. Embryo central, curved, dividing the mealy endosperm into two parts ; 

 cotyledons broad. [Greek, beech-wheat, from the similarity of the grain.] 



About 6 species, natives of Europe and Asia. Type species: Fagopyrum tataricum Gaertn. 



Racemes panicled or corymbose ; angles of the achene not crested. 

 Racemes mostly simple ; angles of the achene crested, undulate. 



F. Fagopyrum. 

 F. tataricum. 



