686 FLORA. 



Involuccls of a few subulate deciduous bracts. Calyx-teeth prominent, triangular. 

 Petals obovatc-cuneate, with a long incurved tip. Stylopodium none. Fruit oval 

 or obovate, flattened dorsally, 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 numer- 

 ous smaller ones irregularly disposed in the thick pericarp. Seed flat. [Greek, 

 many-fillets, or oil-tubes.] A monotypic genus. 



1. Polytaenia Nuttallii DC. PoLYTAENlA. (I. F. f. 2644.) Stem slightly 

 scabrous, leafy, 3-9 dm. high; roots fusiform. Leaves pinnate, the segments 

 deeply pinnatifid or parted. 2-8 cm. long, the lobes ovate, oblong or obovate; umbels 

 6 1 2 -rayed, 2.5-6 cm. broad; rays scabrous, 1-6 cm. long; pedicels finely pubes- 

 cent, 2-4 mm. long; fruit glabrous, 6-10 mm. long, I mm. thick, the margins 

 obtuse, the central part oi both carpels depressed when dry. Dry soil, Mich, and 

 Wis. to Tenn., Kans., Tex. and La. April-May. 



42. OXYPOLIS Raf. [ARCHEMORA DC] 



Perennial glabrous marsh herbs, from clustered tuberous roots, with pinnate or 

 ternate leaves, or in one species the leaves reduced to hollow jointed phyllodes, and 

 compound umbels of white flowers. Involucre none, or of a few linear bracts. 

 Involucels of small bracts, or none. Calyx-teeth acute. Stylopodium thick, conic. 

 Fruit glabrous, dorsally compressed, oval or obovate; dorsal and intermediate ribs 

 slender, the lateral ones winged, strongly nerved along the inner margin of the 

 wing, the carpels appearing as if equally 5-ribbed. Oil-tubes solitary in the inter- 

 vals, 2-6 on the commissural side. Seed-face nearly flat. Four known species, 

 natives of N. Am. 



Leaves all reduced to hollow usually jointed phyllodes. 1. O.filiformis. 



Leaves pinnate ; leaflets linear or lanceolate. 2. O. rzgida. 



i. Oxypolis filiformis (Walt.) Britton. Oxypolis. (I. F. f. -2639.) Stem 

 hollow, 6-12 dm. high. Leaves 2.5-45 cm. long; involucre of several linear- 

 subulate bracts; umbels 4-10 cm. broad, 6-15-rayed; rays 1-5 cm. long; pedicels 

 4-8 mm. long; fruit oval, or slightly obovate. 4-6 mm. long; oil-tubes large. In 

 ponds and swamps, southern Va. to Fla., west to La. Aug. -Sept. Plants collected 

 in Delaware, referred to this species, differ in having broadly oval corky-winged 

 fruit, an inconspicuous disk, slender conic stylopodium and smaller oil-tubes. 



2. Oxypolis rigidus (L.) Raf. CoWBANE. Hemlock. (I. F. f. 2640.) 

 Rather slender, 6-12 dm. high. Leaves petioled. simply pinnate, the lower often 

 3 dm. long or more; leaflets thick, ovate-lanceolate, lanceolate or oblong, entire, or 

 remotely dentate, 3-8 cm. long; involucre of 1-4 bracts, or none; umbels 5-10 cm. 

 broad, 7-25-rayed; rays slender, 2-10 cm. long; pedicels 4-18 mm. long; fruit 

 oval. 5-6 mm. long. 3-4 mm. broad; oil-tubes small. In swamps, N. Y. to Fla., 

 Minn., Mo. and La. Aug. -Sept. 



Oxypolis rfgidus longif61ius (Pursh) Rritton. Leaflets elongated-linear, entire, 2-3 

 mm. wide; fruit smaller. N. J. to S. Car. and Tenn. 



43. SPERMOLEPIS Raf. [LEPTOCAULIS Nutt.] 

 Glabrous slender annuals, the branches often nearly filiform, with dissected 

 petioled leaves, the leaf-segments narrowly linear. Flowers small, white, in un- 

 equal-raved umbels. Involucre none; involucels of a few narrow bracts, or none. 

 Calyx-teeth obsolete. Fruit ovate. Laterally flattened, tuberculate or bristly; peri- 

 carp thick; oil-tubes solitary in the intervals or also under the ribs. 2 on the com- 

 missural side. Stylopodium short, conic. Two species, of the southern U. S. 



Fruit tuberelcd. 1. S. divartcatms. 



Fruit covered with hooked bristles. 2. S. echmatus. 



1. Spermoleois divaricatus (Walt.) Raf. RoUGH-FRUITED SPERMOLEPIS. 

 (I. F. f. 2697.) Similar to Apiastrum patens, but more slender arid more widely 

 branching. Rays of the umbels almost filiform, 14 cm. long, divaricate; pedicels 

 , | 2 mm. long; fruit ovate, densely tuberculate, 1 mm. long; the ribs rather 

 prominent. Neb. to Tex., X. Car. and Fla. Also in ballast at Philadelphia. 

 April-May. 



