^'^""'«-^'- rOLYGONACE.'E. ^ 



'■ °'''''iW'i''^LtvSUt™ """•'" '''«'""'■ '"''"^- ^^^^'"^ -^'"''- 



'■ ''""'keI'^'s\ig''nasVtSell';"''"^' '^' '"--"l-g-g -^ «I"I>--ed to the triangular 



3. Polygonum. Sepals 4 to 6, equal, appressed to the triangular or lenticular akene Styles 



2 or 3 ; stigmas cajutatc. "ij'ca 



TiilDE II EIlIOGONEyR Flownis involurrate (except in Lnstnrriaut). I'eiianth 3-6-iwrte.l. 



base, with nlternato or vertinllate leaves (opposite and sometinu's toothed in J'Uraslegia). 

 without stipules ; juico nearly tiusteless. 



* Involucre unchanged in fruit or wanting : leaves entire. 



-»- Flowei-s capitate, subtended by distinct herbaceous bracts. 



4. Nemacaulis. Stamens 3. Akene ovoid. Annual, prostrate, with radical leaves. 



+■ -f- Involucre tubular or campanulate : perianth corolla-like, 6-cleft or -parted. 



5. Eriogonum. Involucre several-flowered, with 4 to 8 pointless teeth. Flowers exsertcd 

 - r^ ^*'''"en« 9- Akene mostly 3-angled. Annuals or perennials. 



b. Oxytheca. Involucre (ew-flowered, herbaceou.s, with 3 to 5 straight acute or usually awned 

 lohes. I'lowcrs on exserted pedicels, pubescent. Stajnens 9. Akene lenticular. Bracts 

 ternate. Annuals. 



7. Chorizanthe. Involucre 1- (rarely 2-3-) flowered, coriaceous or chartaceous, 3-6-angled 



with J to f) cuspidate often hooked teeth and .sometimes as many cusi.idate divaricate spurs 

 at base. Flowers usually included. Stamens 3, 6 or 9. Akene 3-angIcd. Annuals. 

 •*"+■■•- Involucre none : flowers somewhat axillary. Low annuals. 



8. Lastarriaea. Perianth tubular, subcoriaceous, cuspidutely 6-toothed. Stamens 3. 



9. Hollistena. i'enauth campanulate, 6-cleft, wiiite-woolly. Stamens 9. See page 481. 



• ♦ Involucre bract-like, enlarged in fruit, 2-lobed, Mlowered, 2-saccate on the back. 



10. PteroBtegia Flower sessile, included. Leaves opposite, toothc^d or lobed. Slender annual. 



1. OXYRIA, Hill. Mountain Soukel. 



Flowers perfect. Perianth lierbaceous, of 4 distinct sepals ; the 2 inner erect, 

 appressed and unchanged in fruit, the outer smaller and spreading. Stamens 6. 

 Stigmas 2, sessile, tufted. Akene compressed and thin, broadly 2-winged. Seed 

 flat. Embryo axile in the mealy albumen, slender. — Perennial alpine and arctic 

 herbs, erect, with long-petioled round-reniform mostly radical leaves, and small ob- 

 liquely truncate scarious sheatlis ; flowers small and greenish, in narrowly panicled 

 racemes. — Meisner, DC. Prodr. xiv. 37. 



Only one species is known, in the mountains of Central Asia, besides the following. 



1. O. digyna, Campdera. Rather stout and fleshy, 3 to 18 inches high, gla- 

 brous : leaves an incli or two broad : flowers in scariousbracted fascicles, on short 

 capillary pedicels : sepals often reddish, spatiilate, thin, the outer half as long ns 

 the inner ones, narrower and carinato : akene exceeding the sepals, U lines in diam- 

 eter, entire or emarginate nt each end. — 0. reuiformis, Hook. 



At high altitudes in the Sierra Nevada, in cold wet places among rocks, and in like localities 

 throughout the northern hemisphere, northward to the Arctic Ocean. 



2. RUMEX, Linn. Dock. Sourel. 



Flowers perfect or polygamous or dia-cions. Perianth of G sepals, distinct or 

 nearly so, the outer 3 herbaceous, spreading or rcflexed, the inner larger and some- 



