CHICKWEED FAMILY 269 



None of the bracts scarious. 



Leaves linear to lanceolate, more than four times as long as broad; plants 



perennial, with running rootstocks. 



Petals equalling or exceeding the sepals. 



Plant low. less than 1 dm. liigh. bluish green. 8. A. Jaeta. 



Plant slender, light green, more than 1 dm. high. 



11. A, crassifoUa. 



Petals much shorter than the sepals, or none. 



Sepals with narrow scarious margins, acute; leaves oblong-lanceolate, 

 narrowed at the base; midrib not unusually strong; petals usually 

 lacking. • 12. ^. boreaUs. 



Sepals with broad scarious margins, acuminate; leaves hnear-lanceolate. 



with a strong midrib; petals usually present. 



Leaves 2-8 mm. wide, broadest near the base. 



13. A. brachypetala. 



Leaves 8-15 mm. wide, broadest near the middle. 



14. A. oxyphylla. 



Leaves ovate-lanceolate, ovate or oval, less than four times as long as broad; 



cespitose perennials, except No. 18. 

 Leaves thin. 



Stem glabrous or nearly so. - a • 



Sepals acute or acuminate. 15. A. crispa. 



Sepals obtuse. 56. A. obtusa. 



Stem distinctly pubescent. ,„ ^ , .i. 



Leaves sessile; flowers more or less cymose. 17. A. calycantha. 

 Leaves short-petioled; flowers solitary in the axils. 



18. A. washingtonxana. 



Petals eqiiallmg or exceeding the sepals; branches simple, ascending. 

 Leaves ovate, bluish green, with strong midrib; petiils longer than 



the obtusish sepals i^« A. hdwarasii. 



Leaves oval, bright green; midrib not strong: petals equalling the 

 acute sepals. 19. A. Palmert. 



Petals shorter than the sepals; branches divaricately branched, spread- 

 ijjg 20. A. polygonoides. 



Plant more or less viscid, especiallv the upper portion; perennials with rootstocks. 

 Plant tall. 1-3 dm. high, erect; leaves linear to lanceolate. ^ ^ ,• - 



Leaves Unear or linear-lanceolate. 2-5 mm. wide. 21. A. iyurtisit. 



Leaves lanceolate, 5-10 mm. wide. 22. A. Jamepana. 



^ Plant low. diffusely cespitose; leaves ovate. 2^. A. amencana. 



1. A. media L. Stem diffusely branched, prostrate or ascending, 1-4 dm. 

 long, glabrous except the pubescent lines; leaf-blades 0.5-3.5 cm. long; sepals 

 oblong, glandular-pubescent, about equalling the capsule; petals shorter than the 

 sepals. S. media Cyrill. Chickweed. Waste places, cultivated grounds, etc.: 

 GreenL—Fla.— Calif.— B.C.; W. Ind.; nat. from Eu. Ja-D. 



2. A. nitens (Nutt.) Greene. Stem branched near the base, glabrous or 

 somewhat pubescent below, erect, 1-2 dm. high; basal leaf-blades ovate, acute, 

 4-5 mm, long; stem-leaves 6-10 mm. long; sepals lanceolate, acute, 3-4 mm. 

 long, 3-nerved at the base; petals about half as long as the sepals, or sometimes 

 wanting. S, nitens Nutt. S. praecox A. Nels. \\ et places: w Mont.— Ltah 

 —Calif.— B.C. Son.—SuhmonL Mr-Je. 



3. A. baicalensis Coville. Stem weak, ascendmg, or decumbent at the 

 base, 3-30 cm. high; leaves 6-20 mm. long; bracts lanceolate; sepals 2-2.5 mm. 

 long, glabrous, scarious-margined. S. umbellala Turcz. Around sprmgs and 

 brooks: Mont.— N.M.— Calif.— Ore.; Siberia. Submont.—Alp. Jl-Au. 



4. A. alpestris (Fries) Rydb. Stem 2-4 

 ^ar. 2-4 cm. lone. 2^ mm. wide; bracts 



less 



or lacking. S. alpestris Fries. Wet places: Ont.—Sask.— Colo.— Utah— Alta.; 

 n Eu. Submont. — Mont. Je-Au. 



6. A. longifolia (Muhl.) Britton. Stem sharply 4-angled, 2-5 dm. high; 

 leaves sessile, lance-linear, often ciUate towards the base, 2-6 cm. long, 2-6 mm. 

 wide; bracts lanceolate; branches of the c^-me and pedicels spreadmg; sepals 

 lanceolate, acute, 3-ner\^ed, about 3 mm. long, shorter than the petals b. longt- 

 folia Muhl. Low meadows and swamps: Lab,— Xew-f.—Md.— A.M.— Alaska; 

 Eurasia. Plain — Subalp. My-Au. 



6. A. strictiflora Rydb. Stem 2-5 dm. high, angled; leaves linear-lance- 

 olate, 2-4 cm. lone. 2-4 mm. wide, spreading; pedicels strongly ascendmg or 



