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..
Glabrous, perennial herbs, with pinnate leaves and compound umbels of white flowers. Involucre and involucels none in our species. Calyx-teeth obsolete. Petals inflexed at the apex. Stylopodium thick, low, broadly conic. Fruit ovate, or oblong, more or less compressed. Carpels obscurely 5-angled with slender equal distant ribs; oil-tubes numerous, 2-6 in the intervals. Seed-face flat or slightly convex. [Latin; perhaps from bipinnula, i. e., bipinnate.]
About 75 species, natives of the Old World, the following typical.
Pimpinella Saxifraga L. Sp. Pl. 263. 1753.
Erect, glabrous, 1°-2° high, somewhat branched. Leaves pinnate; segments of the lower 9-19, sharply serrate, or incised, ovate, or nearly orbicular, 8"-12" long; upper leaves shorter-petioled and of fewer segments cut into narrower lobes; flowers white; umbels slender-peduncled, 7-20-rayed; rays slender, 1'-1 1/2' long in fruit; fruit oval, about 1" long.
In waste places, New Brunswick to Pennsylvania!, New Jersey, Delaware and Ohio. Adventive from Europe. June-Oct.
Pimpinella mágna L., a similar European species, taller and with larger leaves, has been found in waste grounds in Pennsylvania.
46. BÉRULA Hoffm.; Bess. Enum. Pl. Volh. 44. 1821.
A glabrous aquatic or marsh perennial, with pinnate leaves, serrate or sometimes incised leaf-segments, and terminal compound umbels of white flowers. Involucre and involucels of several narrow bracts. Calyx-teeth very small. Stylopodium conic; styles short. Fruit subglobose, emarginate at the base, slightly flattened laterally, glabrous, the ribs very slender, the pericarp thick and corky; oil-tubes numerous and close together along the inner side of the pericarp. Seed-face flat. [Latin name of the water cress.]
A monotypic genus of the north temperate zone.
Sium erectum Huds. Fl. Angl. 103. 1762.
Sium angustifolium L. Sp. Pl. Ed. 2, 1872. 1763.
B. erecta Coville, Contr. Nat. Herb. 4: 115. 1893.
Erect, rather stout, much branched, 6'-3° high. Leaflets 7-19, ovate, oval, or linear-oblong, deeply serrate, crenate, laciniate, or lobed, 6"-18" long, 2"-s" wide, those of the upper leaves commonly more laciniate than those of the lower; umbels numerous, short-peduncled, 10-20-rayed; rays 1/2-2 1/2' long in fruit; pedicels 1 1/2"-3" long; fruit less than 1" long, nearly orbicular, somewhat cordate at the base, the ribs inconspicuous.
In swamps and streams, southern Ontario to British Columbia, south to Illinois, Nebraska; in the Rocky Mountains to New Mexico and to California. Also in Europe and Asia. Lesser, narrow-leaved, creeping or water-parsnip. July-Sept.
47. SĚUM [Tourn.] L. Sp. Pl. 251. 1753.
Perennial marsh herbs, with simply pinnate stem-leaves, the lower and basal ones often pinnatisected, and compound large umbels of white flowers. Involucre and involucels of numerous narrow bracts. Calyx-teeth minute. Petals inflexed at the apex. Stylopodium depressed. Styles short. Fruit ovate or oval, somewhat compressed. Carpels with prominent ribs; oil-tubes 1-3 in the intervals. Seed-face flat. [Greek name of a marsh plant.]
About 8 species, natives of the north temperate zone and South Africa. The following are the only ones known to occur in the United States. Type species: Sium latifolium L.
Plant stout, 2o-6o high; leaf-segments 7-17.
Plant weak, 1°-3° high; leaf-segments 3-7.