164 ELEMENTS UF BOTANY. 



P. SATivA L. Parsnip. Root long-conical, fleshy; stem erect, 

 branched, pubescent above, glabrous below, 2-5 ft. high; lower 

 leaves long-petioled, pinnate, the divisions sessile, acute or oval, 

 irregularly incised or lobed, sharply and unevenly serrate, upper 

 leaves similar but much smaller ; umbels numerous, compound, 

 7-15-rayed, rays slender, umbellets 5-10-rayed; fruit smooth, broadly 

 oval, nearly as long as the pedicels, lateral ribs and oil tubes 

 prominent, intermediate ribs reduced to slight ridges. June- 

 August. Escaped from cultivation and sometimes a troublesome 

 weed; root reputed to be poisoijous in its wild state. 



III. THASPIUM. 



Perennial herbs ; stem erect ; leaves 1-2-ternately com- 

 pound; umbels compound, involucre and involucels usually 

 wanting ; flowers yellow or purple ; calyx teeth small, acute ; 

 fruit ovoid or oblong, somewhat laterally compressed ; carpels 

 smooth, strongly ribbed, oil tubes between the ribs. 



T. BARBiNODE (Michx.) Nutt. Hairy Meadow Parsnip. Stem 

 erect, branching above, pubescent at the nodes, 2-7 ft. high ; leaves 

 petioled, 1-2-ternate, slightly pubescent ; leaflets mostly thin, ovate, 

 toothed, incised or lobed toward the apex, entire toward the base; 

 umbels long-peduncled, few-rayed ; fruit oblong, lateral and central 

 ribs strongly winged. ]\Iay-June. Along streams. 



IV. ERYNGIUM. 



Annual, biennial or perennial herbs ; stems erect or creeping ; 

 leaves simple, mostly linear and spiny-toothed ; flowers white 

 or blue, in dense, bracted heads or spikes, flowers bracteo- 

 late ; calyx teeth rigid, persistent ; petals erect, pointed ; styles 

 slender; fruit turbinate, scaly or granular, ribs obsolete, oil 

 tubes usually 5, minute. 



E. AQUATicuM L. Button Snakeroot. Perennial; stem erect, 

 branched above, striate, glaucous, 2-3 ft. high ; leaves linear, often 

 2 ft. or more in length, rigid, glaucous, parallel-veined, fringed with 

 white bristles; bracts shorter than the heads, entire, bracteoles simi- 

 lar but smaller ; flowers white ; fruit scaly. May-July. On damp 

 soil. 



