VOL. II.] 



CARROT FAMILY. 



515 



i. Imperatoria Ostruthium I,. Mas- 



terwort. Felon-grass. Pellitory of 



Spain. (Fig. 2643.) 



Imperatoria Ostruthium I,. Sp. PI. 259. 1/53. 



Glabrous, or sparingly pubescent; stem stout, 

 hollow, erect, 2-5 tall. Leaves ternately di- 

 vided into very broad stalked segments which 

 are often 3-parted nearly or quite to the base, 

 sharply and unequally serrate and often incised, 

 the segments of the long-petioled lower leaves 

 often 5' broad; rays of the umbels and pedicels 

 very numerous, slender; involucre none, or of i 

 or 2 lanceolate bracts; involucel-bracts few, nar- 

 row, deciduous; fruit broadly oval, about i" long. 



In fields, Pocono plateau of Pennsylvania and 

 Michigan. Reported from Newfoundland. Natu- 

 ralized or adventive from Europe. Called also 

 Broad-leaved Hog's Fennel. May-July. 



9. POLYTAENIA DC. Mem. Omb. 53. pi. 13. 1829. 

 Perennial, nearly glabrous herbs, with pinnately decompound leaves, and compound 

 umbels of yellow flowers. Involucre none, or rarely of 1-2 linear bracts. Involucels of a 

 few subulate deciduous bracts. Calyx-teeth prominent, triangular. Petals obovate-cuneate, 

 with a long incurved tip. Stylopodium none. Fruit oval or obovate, much flattened dor- 

 sally, thick and corky; dorsal and intermediate ribs obscure, the lateral ones with thick 

 wings which form a broad margin to the fruit, and are nerved toward the outer margin; oil- 

 tubes 12-18, contiguous, with numerous smaller ones irregularly disposed in the thick peri- 

 carp. Seed flat. [Greek, many-fillets, or oil-tubes.] 



__. A monotypic genus of central North America. 



-r-u A Polytaenia Nuttallii DC. Polytaenia. 



(Fig. 2644.) 



Polytaenia Nuttallii DC. Mem. Omb. 53. pi. ij. 1829. 



Stem slightly scabrous, leafy, i-3 high; roots 

 fusiform. Leaves petioled, or the uppermost 

 smaller and sessile, pinnate, the segments deeply 

 pinnatifid or parted, i / -3 / long, the lobes ovate, ob- 

 long or obovate, dentate or entire; umbels 6-12- 

 rayed, i / -2^ / broad; rays scabrous, ^'-2^' long; 

 pedicels finely pubescent, i // -2 // long; fruit gla- 

 brous, 3"-s" long, 2#"-3^" broad, ft" thick, 

 the margins obtuse, the central part of both car- 

 pels depressed when dry. 



Dry soil, Michigan and Wisconsin to Tennessee, 

 Texas and Louisiana. April-May. 



10. PEUCEDANUM I,. Sp. PI. 245. 1753. 



Perennial herbs, acaulescent or nearly so, from thick fusiform or tuberous roots, with 

 ternate, pinnate, or in our species bipinnate or finely dissected leaves, and compound umbels 

 of white or yellow flowers. Involucre none. Involucels of several or numerous bracts. 

 Calyx-teeth mostly obsolete. Stylopodium depressed or none. Fruit oval, oblong or or- 

 bicular, glabrous or pubescent, dorsally compressed. Carpels with filiform dorsal and inter- 

 mediate ribs, the lateral ones broadly winged; oil-tubes 1-4 (rarely more) in the intervals, 

 2-10 on the commissural side. Seed-face flat or slightly concave. [Name Greek.] 



About i2 species, of wide geographic distribution. In addition to the following, about 47 

 others occur in western North America. 



Flowers white or pinkish. 

 Flowers yellow. 



Fruit glabrous; involucel-bracts united. 

 Plant pubescent. 

 Plant glabrous. 

 Fruit finely pubescent; involucel-bracts linear, distinct. 



i. P. nudicaulc. 



2. P. foeniculaceum. 



3. P. Kingii. 



4. P. villosum. 



