688 FLORA. 



I. Imperatoria Ostruthium L. Masterwort. (I. F. f. 2643.) Glabrous, 

 or sparingly pubescent; stem stout, hollow, erect, 6-15 dm. tall. Leaves ternately 

 divided ii:t<> broad Stalked segments winch are often 3 -parted to the base, sharply 

 serrate and often incised, the segments of the long-petioled lower leaves often 1. 3 

 dm. broad; rays numerous, slender; involucre none, or of I or 2 lanceolate bracts; 

 involucel-bracts lew, narrow, deciduous; fruit about 4 mm. long. In fields, Penn. 

 and Mich. Reported from Newf. Nat. or adventive from Europe. May-July. 



46. PASTINACA L. 



Tall branching herbs, with thick roots, pinnate leaves, and compound umbels 

 of yellow flowers. Involucre and involucels commonly none. Calyx-teeth obsolete. 

 Stylopodium depressed. Fruit oval, glabrous, much flattened dorsally; dorsal and 

 intermediate ribs filiform, the lateral winged, those of the two carpels contiguous 

 and forming a broad margin to the fruit; oil-tubes solitary in the intervals and 2-4 

 on the commissural side. Seed very flat. [Latin pastus, food.] About 7 species, 

 natives of Europe and Asia. 



I. Pastinaca sativa L. Wild Parsnip. (I. F. f. 2642.) Biennial or rarely 

 annual, glabrous, or somewhat downy-pubescent, 6-15 dm. high. Lower and basal 

 leaves petioled, pinnate, often 4.5 dm. long, the segments rather thin, ovate or oval, 

 obtuse, sessile, lobed or incised and sharply dentate, 2-8 cm. long; umbels 5-15 

 cm. broad, 7-15-rayed, the rays 1-5 cm. long; pedicels 6-12 mm. long in fruit; fruit 

 broadly oval, 5-7 mm. long, the oil-tubes conspicuous. Roadsides and waste places, 

 a common weed in nearly all parts of our area. Nat. from Europe. June-Sept. 



47. HERACL-&UM L. 



Erect perennial herbs, with ternately compound leaves, and compound umbels 

 of white flowers. Bracts of the involucre few and deciduous, or none. Involucels 

 of numerous linear bracts. Calyx-teeth obsolete or small. Petals cuneate, or 

 clawed; those of the outer flowers dilated and obcordate or 2-lobed. -Stylopodium 

 thick, conic. Fruit flattened dorsally, broadly oval, obovate or orbicular; dorsal 

 and intermediate ribs filiform, the lateral ones broadly winged and the wings nerved 

 near the outer margin; oil -tubes extending only to about the middle of the carpels, 

 conspicuous, 1 in each interval, 2-4 on the commissural side. [Greek, to Hercu- 

 les]. About 60 species, of the northern hemisphere, only the following in N. Am. 



I. Heracleum lanatum Michx. Cow-parsnip. (I. F. f. 2641.) Verystout, 

 tomentose-pubescent, 1-3 m. high, the stem ridged, often 5 cm. thick at the base. 

 Leaves petioled, very pubescent beneath, the segments broadly ovate, or orbicular, 

 cordate, stalked, lobed and sharply serrate, rather thin, 7— 15 cm. broad; petioles 

 much inflated; umbels 1.5-3 dm. broad, 8-30-rayed, the rays stout, 5-10 cm. long; 

 fruit 8-12 mm. long, 6-9 mm. broad, finely pubescent, emarginate at the summit. 

 In moist ground, Newf. to Alaska, N. Car., Mo., Utah and Cal. June-July. 



48. DAUCUS L. 



Biennial or annual, mostly hispid-pubescent herbs, with pinnately decompound 

 leaves, and compound umbels of white or reddish flowers. Involucre of several 

 foliaceous bracts in our species. Involucels of numerous entire or toothed bracts. 

 Calyx-teeth obsolete. Petals obovate, the apex inflexed. those of the outer flowers 

 often dilated and 2-lobed. Umbels concave in fruit. Fruit somewhat flattened 

 dorsally. Primary ribs 5, slender. Secondary ribs 4. winged, each bearing a row 

 of barbed prickles. Oil-tul)es solitary under the secondary ribs, and 2 on the com- 

 missural side of each carpel. [The ancient Greek name.] About 25 species, of 

 wide distribution. 



Stem retrorsclv hispid: leaf-segments linear. 1. D. pusillus. 



Stem bristly pubescent; leaf-segments lanceolate. 2. D. Caro/a. 



1. Daucus pusillus Michx. American Carrot. Biennial, 3 cm. -6 dm. high, 

 closely resembling the following species. leaves finely dissected, the segments 

 linear, acute; umbels 2-8 em. broad; pedicels very unequal. N. Car. to Fla., 

 Mo.. M< \. uid C\\. April June, 



2. Daucus Carota L. Wild Carrot. (I. F. f. 2632.) Usually biennial, 

 3 i) dm. high, the root fleshy, conic. Lowe." and basal leaves 2-3pinnatc, the 



