35^ FLORA. 



lique, 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-parted, persistent 

 and unchanged in fruit, the segments petaloid, shorter than the achene. Stamens 

 8; filaments filiform, glabrous. Ovary 1 -celled, i-ovuled; style 3-parted; stigmas 

 capitate. Achene 3 -angled. Embryo central, dividing the mealy endosperm 

 into two parts; cotyledons broad. [Greek, beech-wheat, from the similarity of the 

 grain.] About 6 species, native of Europe and Asia. 



Racemes panicled or corymbose; angles of the achene not crested. 1. F. Fagopyrum. 

 Racemes mostly simple; angles of the achene crested, undulate. 2. F. Tataricum. 



i. Fagopyrum Fagopyrum (L.) Karst. Buckwheat. (I. F. f. 13 16.) 



Annual, glabrous except at the nodes, stem 3-9 dm. high. Leaves hastate, 

 2.5-7.5 cm. long, abruptly narrowed above the middle, acuminate, the nerves on 

 the lower surface slightly scurfy; ocreae brittle and fugacious; racemes mostly 

 panicled, sometimes corymbose, many-flowered, erector inclined to droop; pedi- 

 cels as long as the calyx; calyx-segments white or whitish; stamens included; 

 style-branches deflexed in fruit; achene acute, 5 mm. long, about twice as long as 

 the calyx, its faces pinnately-striate when mature, the angles acute, not crested. 

 In waste places, and persistent in fields after cultivation. Reported from almost 

 all parts of the northern U. S. and southern British America. Native of eastern 

 Europe or western Asia. June-Sept. \F. esculentum Moench.] 



2. Fagopyrum Tataricum (L.) Gaertn. Tartary Buckwheat. (I. F. f. 

 13 1 7.) Annual, similar to the preceding species, but the leaves deltoid-hastate, or 

 oblong-hastate, often broader than long, 2.5-10 cm. wide, acute or short-acuminate 

 at the apex; racemes terminal and axillary, mostly solitary, simple and few- 

 flowered, long-pedur.cled; flowers whitish, short-pedicelled; achene subacute, 5 

 mm. long, its angles crested with three prominent lobes above the middle, its faces 

 pinnately sulcate from a conspicuous groove. In waste places, eastern Canada 

 and New England. Adventive from Asia. Summer. 



6. POLYGONUM L. (See Appendix.) 



Annual or perennial, terrestrial or aquatic herbs, some species woody, with erect, 

 prostrate, climbing or floating stems, alternate entire leaves, continuous with, or 

 jointed to the cylindric funnelform or two-lobed, often lacerate or fringed ocreae, 

 Flowers normally perfect, green, white, pink or purple, variously clustered, the 

 clusters terminal or axillary. Pedicels jointed, subtended by ocreae or ocreolae; 

 calyx 4-5-parted or 4-5 -cleft, the outer sepals or segments somewhat larger than the 

 inner, stamens 5-9, included or exserted; filaments filiform, or dilated at the base, 

 glabrous; style 2-3 -parted or 2-3-cleft, its branches included or exserted; stigmas 

 capitate; achene lenticular or 3-angled (rarely 4 angled), invested by or exceeding 

 the calyx. Embryo near the end of the seed, in one of its angles. [Greek, many- 

 knees from the swollen joints of some species.] About 200 species, of wide geographic 

 distribution. Besides the following, some 33 others occur in the western and 

 southern parts of North America. 



1. Flowers in terminal spike like racemes; calyx 5-cleft or 5-parted; stem not twining. 

 Raceme solitary ; alpine species ; perennial, not aquatic. 1. P. viviparum. 



Racemes solitary or 2 ; aquatic or swamp species; perennials. 



Leaves oblong, elliptic, or elliptic-lanceolate, not acuminate. 2. P. amphibium. 



Leaves narrowly lanceolate, or oblong-lanceolate, not acuminate. 



3. P. Hartwrightii. 

 Leaves ovate-lanceolate, or oblong-lanceolate, usually acuminate. 



4. P. emersum. 

 Racemes several or numerous ; annuals or perennials, mostly terrestrial. 



Ocreae naked or ciliolate, their limbs not spreading. 

 Racemes drooping. 



Achene ovoid; style 2 parted to near the base. 6. P. incamatum, 



Achene broadly oblong-ovoid; style 2-cleft to-below the middle. 



7. P. lapatJii/olium. 



