BUCKWHEAT FAMILY 59 



long, the lobes oblong, with narrow white or roseate margins; stamens 5-8; achene 3-angled, 

 2-2.5 mm. long, ovoid-oblong, slightly exceeding the calyx, black, smooth and shining. 



Meadows and rocky slopes, Boreal Zones; British Columbia and the Cascade Mountains, Washington, to 

 the southern Sierra Nevada, California, east to Montana and Colorado. Type locality: Wasatch and Uinta 

 Mountains, 9,000-11,000 feet altitude, Utah. July-Sept. 



13. Polygonum sawatchense Small. Sawatch Knotweed. Fig. 1455. 



Polygonum sawatchense Small, Bull. Torrey Club 20: 213. 1893. 



Annual with dull green foliage, the stems slender, erect, 5-20 cm. high, simple or commonly 

 branched from near the base, more or less papillose throughout, obscurely 4-angled or winged 

 below the stipules. Leaves obovate to oblanceolate or the uppermost nearly linear, 5-20 mm. 

 long, acute at apex, narrowed to the sessile base, flat or revolute ; conspicuously articulate at the 

 junction with the sheath, midrib prominent and often keeled ; stipule-sheaths 2-parted, at length 

 lacerate ; flowers borne in clusters of 2-3 in the axils of nearly all the leaves from near the base 

 to the top ; calyx green, 2-3 mm. long, the lobes oblong, a little paler on the margins ; stamens 

 6-8 ; style cleft to the base, very short ; achene 3-angled, oblong, smooth, black and shiny. 



Drv ground. Arid Transition Zone; Klickitat County, Washington, to the eastern slopes of the central 

 Sierra Nevada, California, east to Dakota and Colorado. Type locality : Sawatch Mountains, Colorado. July-Sept. 



14. Polygonum spergulariaeforme Meisn. Fall or Spurry Knotweed. Fig. 1456. 



Polygonum spergulariaeforme Meisn. ex Small, Bull. Torrey Club 19: 366. 1892. 

 Polygonum coarctatum Dougl. ex Meisn. in DC. Prod. 14: 101. 1856. Not Meisn. 1826. 



Annual, erect, slender and wiry, simple or usually rather strictly branched or diffuse, 1-4 dm. 

 high, scurfy throughout. Leaves linear to linear-lanceolate, 0.5-3 cm. long, acute at apex, sessile, 

 often revolute, conspicuously articulate with the stipule-sheaths ; flowers 2-4 in the axils, appear- 

 ing as spicate racemes above by the shortening of the internodes, at length nodding ; calyx-lobes 

 roseate to whitish, with a very narrow darker midrib, 2.5-3 mm. long; stamens 8; style 3-cleft 

 to the middle ; achene 3-angled, 3-4 mm. long, oblong, black, smooth and shining or somewhat 

 granular at the apex. 



Dry sterile soils, mainly Arid Transition Zone; British Columbia to the Sierra Nevada and Humboldt County, 

 California, east to Colorado. Type locality: not designated. June-Sept. 



15. Polygonum Nuttallii Small. Nuttall's Knotweed. Fig. 1457. 



Polygonum intermedium Nutt. ex S. Wats. Proc. Amer. Acad. 17: 378. 1882. Not Ehrh. 1791. 

 Polygonum Nuttallii Small, Mem. Dept. Bot. Columbia Univ. 1: 132. pi. 53. 1895. 



Annual, glabrous or somewhat scurfy, especially at the nodes and on the margins of the 

 leaf, the stems slender and wiry, erect, simple or branched, dark red, 4-angled and often nar- 

 rowly winged, 5-25 cm. high. Leaves linear-lanceolate to linear-oblanceolate, 1-3 cm. long, acute 

 at both ends, subsessile, glaucescent beneath, slightly revolute-margined ; stipule-sheaths 3-4 mm. 

 long becoming lacerate in age; flowers 2-3 in the upper axils, appearing as terminal bracted 

 racemes, short-pedicelled ; calyx 2.5 mm. long, the lobes greenish, with roseate margins; fila- 

 ments conspicuously dilated at the base ; achenes 3-angled, ovoid, 2 mm. long, black, smooth and 



shinv. 



Usually in gravelly or sandy soils, Canadian and Transition Zones; British Columbia south in Olympic and 

 Cascade Mountains to northern Oregon. Type locality: "On bluffs of the Columbia plains. July-Sept. 



16. Polygonum Kelloggii Greene. Kellogg's Knotweed. Fig. 1458. 



Polygonum imbricatum Nutt. ex. S. Wats. Amer. Nat. 7: 665. 1873. Not Raf. 1836. 



Polygonum Kelloggii Greene, Fl. Fran. 134. 1891. 



Polygonum Watsonii Small, Mem. Dept. Bot. Columbia Univ. 1: 138. pi. 56, as to synonymic type. 1895. 



Annual, glabrous throughout, the stems erect and simple or divergently branched from the 

 base, 3-8 cm. high, internodes very short. Leaves linear or linear-lanceolate, 5-10 mm. long, 

 crowded on the branches, but spreading and not imbricate; flowers in a leafy-bracted spike 

 5-30 mm. long ; bracts linear to lanceolate, green or with a very narrow white margin, spreading 

 or on older plants those toward the apex appressed-ascending ; pedicels less than 1 mm. long ; 

 calyx scarcely 2 mm. long, green with a white margin ; stamens 3 ; style wanting or very short ; 

 achene 3-angled, 1 . 5 mm. long, ovoid, light brown, dull and smooth or granular toward the apex. 



Gravelly or sandy slopes, Canadian and Hudsonian Zones; Cascade Mountains Washington, south to the 

 mountains of southern California, east to Colorado. Type locality: "common in the Donner Lake region of the 

 Sierra," California. June-Sept. 



Polygonum esotericum Wheeler, Rhodora 40: 309. 1938. Smooth brown seeds and subsessile stigma- 

 lobes as in P. Kelloggii, but anther-bearing stamens 8 or the inner 3 anther-bearing and the 5 outer rudimentary, 

 flowers in the axils of all but the lowest leaves forming a slender elongated bracted spike; bracts lanceolate, 

 narrowly white-margined. Known only from the type collection: dry seasonally submersed adobe bed of artificial 

 lake, Rim Rock Valley Reservoir, Modoc County, California. 



17. Polygonum polygaloides Meisn. White-margined Knotweed. Fig. 1459. 



Polygonum polygaloides Meisn. in DC. Prod. 14: 101. 1856. 



Annual, glabrous, the stems erect, 5-20 cm. high, simple or usually corymbosely branched. 

 Leaves narrowlv linear, 1-3 cm. long, acute, conspicuously articulate to sheath; floral bracts 

 ascending, crowded and imbricate, forming short axillary and terminal racemes, oblong with 

 conspicuous white-scarious margins ; flowers several in each axil ; calyx 2 mm. long, the lobes 

 lanceolate, with a dark rose midrib and white or pinkish margins ; stamens 8 ; style 3-parted to 

 below the middle; achene 3-angled, ovoid, 1-1.5 mm. long, dull black and striate. 



Moist ground, Arid Transition Zone; Spokane County, Washington, to northeastern Oregon, east to Mon- 

 tana. Type locality: Clearwater River, Idaho. June-July. 



