oDO rOLIGONACK.i:. (iUCKWHKAT lAMlLY.) 



§ 3. Avici'l.AUiA. Flowers arilhiri/, siiujle or 2-3 Imjitlicr : stamens 8, r</ip/y 

 fewer: sli;/mas 3, ncar/i/ sissi/e : urheuiiim 3-an(jlid : coli/lidoiis inrumbeitt : ulhii- 

 men honiif : slieaths scarious, 2 ~3-]iurted, lacerated: leaves small. 



10. P, aviculare, L. Stem prostrate, diffuse, short -jointed ; leaves sessile 

 (J' long), olilon-i^-linear or lanceolate, obtuse, longer than the 3-eUft sheaths ; 

 flowers clustered, nearly sessile, greenish-white, longer than the dull achenium ; 

 stamens mostly 5. — Waste jilaces and along roads, coninion. — Var. EJtKCTUM. 

 (P. creetum, L.) Stem stouter, erect or ascending, leaves larger (1'- 1|' long), 

 ohiong. — "With the preceding. — Var. littohai.e. (V. niaiiiinium, L. P. 

 glaueum, Niitt.) Stem long (lo--2°), prostrate, rigid, short-jointed; leaves 

 small (4''-G"), oblong-linear, glaucous; the uppermost imbricated and scarcely 

 longer than the more conspicuous silvery sheaths ; calyx reddish-white, shorter 

 than the smooth achenium. — Sea-coast sands, Georgia, and northward. 



11. P. tenue, Michx. Smooth; stem erect, branched, sharply angled, 

 slender; leaves scattered, linear, acute ; sheaths small, fringed ; flowers mostly 

 solitary, greenish-white ; achenium smooth and shining. — Dry rocks in the 

 upper districts. July - Sept. (i) — Stem 6' - 8' high. Leaves G" - 12" long. 



§ 4. TovARiA. Flowers scattered in a long and slender spike: cali/.r A-parted : 

 stamens 5, included : styles 2, exserted, persistent : achenium lenticular : cotjlcdons 

 ac.cunihcnt. 



12. P. Virginianura, L. Stem erect, smooth below ; the upper portion, 

 like the leaves and spikes, more or less hairy ; leaves large, ovate or ovate-lance- 

 olate, acute at each end ; sheaths cylindrical, hairy, fringed ; flowers greenish, 

 curved ; styles at length hooked at the apex. — Dry rich soil, Florida, and 

 northward. Aug. and Sept. U — Plant 2° - 4° high. Leaves 3' - 5' long, 

 U' - 2i' wide. Spike 6' - 1 2' long. 



§ 5. EcHiNOCAULON'. Flowers in teimlnal clusters: calj/x 4 - ti-pai-ted : stamens 

 6 or 8 : styles 2 - 3 : achenium lenticular or 3-angled: cotyledons accundxnt. — 

 Stems weak, hranchinfj, armed on the angles, petioles, jJt. with recurved prickles. 



13. P. arifolium, L. Leaves hastate, acuminate, membranaceous, mi- 

 nutely dotted and hairy, long-petioled, the lobes acute ; peduncles rather short, 

 bristly; flowers wliitc, somewhat spiked; stamens 6 ; styles 2; achenium len- 

 ticular. — Kicc fields and wet places. South Carolina, and northward. June- 

 Ott. ® — Stems 2° - 3° long. Leaves 3' - 4' long. Calyx often 4 -parted. 



14. P. sagittatum, L. Leaves small, sagittate, acute, short-pctioled, 

 smooth ; peduncles elongated, smooth ; flowers white, capitate ; stamens 8 ; 

 styles 3; achenium 3-angled. — Wet places, Florida, and northward. June- 

 Oct. Q) — Stem \°-3° long. Leaves 1 ' - 2' long. 



§ 6. TiNiAniA. Flowers in axillary clusters or racemes: calyx greenish white, 

 b-parted, the outer lobes keeled or winged on the back : stamens 8 : styles 3, \-ery 

 short: achenium 3-angled: cotyledons accumbent. — Annuals, with twining stems 

 and cordate leaves. 



15. P. Convolvulus, L. Stem roughish, prostrate or twining, or when 

 small erect ; leaves long-petioled, sagittate-cordate, acuminate, the lobes acute or 



