280 ORDER 104. POLYGON ACE^E. 



ent. Sta. t 4. Fruit 5-ribbed, truncate at apex, 1-seeded. (T) Leaves 

 petiolate. Flowers veiy small. 



B. erceta L. Glabrous ; Ivs. ovate, wavy, pale beneath ; clusters 3-6-flwd., distant m 



a strict panicle with filiform branchlets. Sands, S. 2 4f. June Sept. 

 B. liirsiita, and B. 'viscosa, grow in S. Fla.. according to Dr. Chapman. 



ORDER CIV. POLYGONACE^E. SORKELWORTS. 



Herbs (rarely shrubs) with alternate leaves and mostly sheathing stipules 

 (ochrece) surrounding the stem above each tumid joint. Flower** mostly 

 perfect. Perianth (or calyx) 3-6-cleft, mostly colored, imbricated in bud 

 and persistent Stamens 4 15. Ovary 1-celled, free, with a single, erect 

 ovule. Styles or stigmas 2 or 3. Fruit a 3-angled achenium enclosed in 

 the calyx. Seed erect, albuminous, with a curved embryo. Figs. 147, 

 151-4, 286, 304, 313, 337, 521. 



| Ochreae, or sheathing stipules, present at each joint... (6) 



$ Ochreae none. a Flowers in involncrate umbels, 6-sepalled .ERIOGOXUM. 1 



a Flowers in bracted racemes, 5-sepalled. Stems with tendrils BBDNNICHIA. 2 



6 Sepals 4, equal by pairs. Stamens 6. White Mountains: rare OXYRIA. 3 



6 Sepals 6, all similar. Stamens 9. In gardens: common RHEUM 4 



& Sepals 6, the 3 inner increasing, tuberculate RUMEX. 5 



h Sepals 5 (in one Polygonum 4 irregular). ..(<) 



e Sepals all or the 3 inner Pinged. Pedicels solitary THYSANELLA. 6 



r Sepals all entire, x op<', or 3 closed on the fruit. Pedicels solitary POLYGONELLA. 7 



x open at base of fruit. Pedicels fascicled FAGOPYRUM. 8 



x closed on the angular fruit. Herbs POLYCONUM. 9 



x combined with the round fruit. Trees. Fla COCCOLOBUS. 



1. ERIOQONUM, MX. Fls. many in each common 5-toothed involu 

 ere. Cal. deeply 5-cleft. Sta. 9, sty. 3. Ach. 3-angled or 3-lobed. Herbs 

 clothed with down or wool. Lvs. alternate, exstipulate, mostly at the base 

 of the stem, the upper bract-like, often whorled at the forks of the umbel 

 late inflorescence. Very abundant in the Pacific States. June Aug. 



1 E. tomentosum MX. Lower ITS. crowded, oblong-obovate, rusty-white beneath, 



the upper whorled in 3's ; involucre sessile ; calyx colored. 11 Dry soils, S. 2 3f. 



2 E. longlfollum N. Lower Ivs. crowded, oblong-linear, white beneath, the upper 



scattered ; involucre pedunculate ; calyx green, woolly. Fla., and W. 2 4f. 



2. BRUNNIOHIA, Banks. Calyx colored, 5-parted, lobes oblong, at 

 length increased and closed on the obscurely 3-angled achenium. Fil. 8, 

 capillary, styles 3, slender, stigmas entire. ^ Tendrils from the ends of 

 the branches. Flowers racemed, greenish. 



B. clrrliosa Banks. A smooth, shrubby vine, 10 20f, on river banks, Car. to Fla., 

 and W. Leaves cordate to ovate, entire. Sheaths obsolete. May. 



3. OXYRIA, R. Br. MOUNTAIN SORREL. Cal. herbaceous, 4-sepalled, 

 the 2 inner sepals erect, larger, the 2 outer reflexed. Ach. lens-shaped, 

 thin, girt with a broad, membranous wing. Sta. 6, equal. Stig. 2, sessile, 

 penicillate. 1C Low, nearly acaulescent, alpine plants. 



O. renlformis Hook (or digyna Camp.) Root leaves on long stalks, reniform ; outer 

 sepals i a long as the inner ; fruit orbicular. White Mountains, and N. 3 4'. Jtm\ 



