PAM. 133. 105 



1. Flowers in dense capitate or elongated spikia; — herbs with erect or 

 creeping stems and mostly spiny-toothed leaves; calyx-lobes 

 acute or spinous; petals inflexed; fruit slightly flattened lat- 

 erally. Spring and Summer. - - Eryngium, BhU M Snake-root 

 E. Baldwinii. Stems with slender branches at the base; basV | oblong; 

 long-petioled; stem-leaves 3-parted with linear segments; bracts and b 

 lets subulate; fruit tuberculate. In sandy soil. 



E. Floridanum. Stems sparingly branched; basal leaves narrowly oblong, long- 

 petioled; upper-leaves long-linear, sessile; bracts and bractlets linear, sharp- 

 pointed; fruit crowned with the calyx. In brackish marshes. 



E. aromaticum. Stems with ascending branches at the base, corymbose near 

 the top; leaves pinnately parted; setaceous to spine-tipped; bracts 3-cleft. 

 bractlets 3-toothed; fruit crowned with the calyx. In dry pineland. 



E. aquaticum (yuccaf oliunv . Stems corymbose above; leaves linear, bristly 

 on the margins, their bases folded around the stem; bracts and bractlets 

 lanceolate, strongly veined; fruit scaly. In low ground. 



1. Flowers in compound umbels. ---------2 



2. Fruit smooth or slightly roughened, .------.3 



2. Fruit with a row of barbed bristles on the winged, secondary ribs; — 



caulescent herbs with rough-pubescent foliage; leaves pinnately 

 decompound; involucres and involucels various or wanting; 

 calyx truncate; petals white, often unequal; fruit dorsally flat- 

 tened, --------- Daucus, Carrot 



D. Carota. Stems channeled; flowers white, the central one of the umbel often 

 purple. Cultivated. 



2. Fruit armed with hooked bristles, carpels without ribs; — caulescent 



herbs; leaves pinnatifid or palmately 3-7 foliate; flowers usually 

 unisexal. in irregular compound few-rayed umbels; bracts of 

 the involucres resembling the leaves; sepals 5. petals emargi- 

 nate, white, yellowish or purple; fruit somewhat dorsally flat- 

 tened. ------ Sanicula, Black Snake-root 



S. Floridana. Stems solitary, leafy, branched; leaves 3-5 parted with yellowish 

 spiny-cuspidate teeth; branches of the umbel slender, dichotomous; sterile 

 flowers 1-3, nearly sessile; involucre of minute bracts; fruit very small. Sandy 

 soil. Summer. 



3. Fruit laterally flattened; wingless, -------.4 



3. Fruit dorsally flattened. - -8 



4. Calyx-limb minute or none, ---------5 



4. Calyx-limb 5-toothed; — herbs with tuberous roots and pinnately com- 



pound or decompound leaves; bracts few or none, bractlets 

 small, several; petals white, the tips inflexed; fruit slightly flat- 

 tened. In marshes. Summer. 



Cicuta, Water Hemlock or Poison Hemlock 

 C. macula ta. Stems tall, with purple ridges, branching above; leaves twice 

 or thrice compound, petioles of lower leaves long, those of upper leaves 

 short and dilated; bracts linear-subulate, deciduous; rays numerous, un- 

 equal; flowers white; fruit oval or ovoid, not constricted at the con. 

 sure; vittae large. 



5. Leaves dissected into narrow segments; — slender branching herbs; 



no bracts and only a few narrow bractlets; petals white; fruit 



slightly flattened, tuberculate; seeds angled, Spermolepis 'Leptocaulis) 



