Oxypolis rigidior (Linnaeus) Rafinesque. Common name: Cowbane, Pig-potato. Phenology: Aug-Oct; Oct-Nov. Habitat: Bogs, seepages, swamps, wet meadows, streambanks. Distribution: NY west to MN and south to n. FL and TX.
ID notes: Very variable in the size, shape, and toothing/lobing of the leaflets.
Origin/Endemic status: Native
Synonymy ⓘ: = Ar, C, Can, Fl7, FNA13, G, GW2, K4, MC, Mi, Mo2, NcTx, NY, Ok, Pa, RAB, Tat, Tn, Tx, Va, W, WH3; > Oxypolis longifolia (Pursh) Small — S13; > Oxypolis rigidior (L.) Raf. — S, S13; > Oxypolis rigidior (L.) Raf. var. ambigua (Nutt.) Rob. — F, Il, WV; > Oxypolis rigidior (L.) Raf. var. rigidior — F, Il, WV; > Oxypolis turgida Small — S; Sium rigidius Linnaeus. Basionym: Sium rigidius L. 1753
Links to other floras: = Oxypolis rigidior - FNA13
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Wetland Indicator Status:
- Atlantic and Gulf Coastal Plain: OBL
- Eastern Mountains and Piedmont: OBL
- Great Plains: OBL
- Midwest: OBL
- Northcentral & Northeast: OBL
Heliophily ⓘ: 6
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Horticultural Information
Intro: Erect perennial of bogs, seepages, swamps, wet meadows and stream banks.
Stems: Stems stout or slender, few-branched, smooth.
Leaves: Leaves alternate and on long petioles (reduced upward) with sheathing bases, up to 12 in. long, once pinnately divided into 5-11 oblong to lance-shaped segments with netted veins and widely spaced teeth toward the tip, smooth.
Inforescence:
Flowers: Flowers in flat-topped, compound umbel (3-5 in. wide) at top of stem, with a few smaller umbels from upper leaf axils; white; 1/8 in. wide; consisting of 5 upcurved to spreading petals, 5 stamens with white anthers and an ovary with pistil.
Fruits: Fruit a joined pair of oval, ridged seeds that are flat on one side.
Comments: Poisonous to livestock.
Height: 2-5 ft.
plant sale text:
bloom table text:
description: Erect perennial of bogs, seepages, swamps, wet meadows and stream banks.
stems: Stems stout or slender, few-branched, smooth.
leaves: Leaves alternate and on long petioles (reduced upward) with sheathing bases, up to 12 in. long, once pinnately divided into 5-11 oblong to lance-shaped segments with netted veins and widely spaced teeth toward the tip, smooth.
inflorescence:
flowers: Flowers in flat-topped, compound umbel (3-5 in. wide) at top of stem, with a few smaller umbels from upper leaf axils; white; 1/8 in. wide; consisting of 5 upcurved to spreading petals, 5 stamens with white anthers and an ovary with pistil.
fruits: Fruit a joined pair of oval, ridged seeds that are flat on one side.
comments: Poisonous to livestock.
cultural notes:
germination code:
native range: eastern North America
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