This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Rather slender, 2°-6° high, the umbels and upper part of the stem densely tomentose-canescent. Lower leaves ternate or biternate, often 1° long, the divisions pinnate, the segments thick, oval to lanceolate, equally and rather finely dentate, obtuse or obtusish, 1'-2' long, upper leaves mostly reduced to sheathing petioles; umbels 2'-4' broad, 7-30-rayed; rays slender, l'-l 1/2' long; pedicels about 2" long; fruit broadly oval, emarginate at the base, 3" long, finely pubescent; lateral wings about as broad as the carpels; oil-tubes generally 3-6 in the intervals; seed adhering to the pericarp.
In dry soil, Connecticut to Florida, Minnesota, Tennessee and Missouri. Ascends to 3200 ft. in Virginia. Aunt Jerichos. July-Aug.
Angelica sylvestris L., of Europe, which resembles this species, but is less pubescent, with ovate to lanceolate acute leaflets, glabrous fruit, and oil-tubes mostly only one in each interval, has been found on Cape Breton Island.
20. OXỲPOLIS Raf. Neogen. 2. 1825.
[Tiedemannia DC. Mem. Omb. 51. 1829.]
[Archemora DC. Mem. Omb. 52. 1829.]
Erect perennial glabrous marsh herbs, with clustered tuberous roots, pinnate or ternate leaves, or in one species the leaves reduced to hollow jointed phyllodia, and compound umbels of white flowers. Involucre of a few linear bracts or wanting. Involucels of several 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 intervals, 2-6 on the commissural side. Seed-face nearly flat.
Five known species, natives of North America. Type species: Slum rigidius L.
Leaves all reduced to hollow usually jointed phyllodia.
Leaves pinnate; leaflets linear or lanceolate.
Oenanthe filiformis Walt. Fl. Cat. 113. 1788. Oenanthe teretifolia Muhl. Cat. 31. 1813. Tiedemannia teretifolia DC Mem. Omb. 51. pl. 12. 1829. Oxypolis filiformis Britton, Mem. Torr. Club 5: 239. 1894.
Stem hollow, 2°-6° high. Leaves reduced to linear hollow usually jointed acute phyllodia 1-18' long; involucre of several linear-subulate bracts; umbels 2-4' broad, 6-15-rayedi; rays slender, 1/2'-2' long; pedicels 2"-4" long; fruit oval, 01 slightly obovate, 2"-3" long; oil-tubes large.
In ponds and swamps, southern Virginia to Florida, west to Louisiana. 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. Water-dropwort.
Sium rigidius L. Sp. Pl. 251. 1753.
O. rigida Raf.; Ser. Bull. Bot. 218. 1830.
O. longifolius Britton, Mem. Torr. Club 5: 239
1894. Sium longifolium Pursh, Fl. Am. Sept. 194. 1814.
Rather slender, 2°-6° high. Leaves simply pinnate, the lower often 1° long or more; leaflets thick, ovate-lanceolate, lanceolate-linear or oblong, entire, or remotely dentate, 1 1/2' - 3 long, 3"-12" wide; umbels 2'-4' broad, 7-25-rayed; rays slender, 1'-4' long; pedicels 2"-9" long; fruit oval, 2 1/2"-3" long, 1 1/2"-2" broad; oil-tubes small.
In swamps, New York to Florida, Minnesota, Missouri and Louisiana. Aug.-Sept. Pig-potato.