Streptopus amplexifolius

claspleaf twistedstalk

Liliaceae

The Basics

Taxonomy: Kingdom Plantae (plants). Subkingdom - Tracheobionta (vascular plants). Superdivision - Spermatophyta (seed plants). Division - Magnoliophyta (flowering plants). Class - Liliopsida (monocotyledons). Subclass - Liliidae. Order - Liliales. Family - Liliaceae (lily family). Genus - Streptopus Michx. (twistedstalk). Species - Streptopus amplexifolius (L.) DC. (claspleaf twistedstalk).

Ecology: Moist, shaded areas; 250-1700 m. Klamath Ranges, High North Coast Ranges, High Cascade Range, n High Sierra Nevada, Modoc Plateau; to Alaska, central North America. May-Jun.

Identification

Streptopus amplexifolius has greenish white flowers and clasping leaves. It is found from Alberta to Newfoundland south to Virginia, North Carolina, and Tennessee, and in the north-central United States from Michigan to Minnesota.

Twisted-stalk is an herbaceous perennial with a mostly hairless, often branched stem that may grow to 3 feet (1 m) in height. The leaves are alternately arranged, thin in texture, hairless, lance or egg-shaped, clasping the stem at the base and pointed at the tip, 2-5 inches (5-13 cm) in length and ¾-2 inches (2-5 cm) in width, and without teeth or hairs on the margin. The greenish-white flowers, appearing in May and June, have 6 petal-like segments about 3/8 inch (1 cm) in length that bend outward from their middle. The flowers generally occur singly or in pairs and attach to stalks from the bases of the middle and upper leaves. The fruit is berry-like, reddish at maturity, and contains many minute seeds.

Roots: Rhizome thick; roots thick, fibrous.

Stem: 30-100 cm, much-branched, glabrous to densely hairy.

Leaf: sessile, 5-15 cm, 2-5 cm wide, entire or minute-dentate, glaucous below, base cordate, clasping.

Threats

Logging and clearing in mountain coves and boulderfields.

Reproduction

Flower: 9-15 mm, bell-shaped; perianth parts narrowly lance-oblong, spreading to recurved at tips, white, tinged yellow-green, outer flat, inner keeled, narrower, clasping stamens; stamens 6, outer filaments 1 mm, inner 2-3 mm, anthers attached at base; ovary superior, chambers 3, style 1, 4-5 mm, thick, entire or 3-lobed.

Fruit: berry, 10-15 mm, yellow or red.

Seed: many, 3 mm, pale yellow, grooved.

Species Distribution

Citation

USDA Plant Database
USDA, NRCS. 2016. The PLANTS Database (http://plants.usda.gov, 4 February 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA.

Flora of North America
Flora of North America Editorial Committee, eds.  1993+.  Flora of North America North of Mexico.  19+ vols.  New York and Oxford.

Intermountain Herbarium
Consortium of Intermountain Herbaria. 2016. http//:intermountainbiota.org/portal/index.php. Accessed on February 04.

Burke Museum Plant Image Collection
The plant image collection at the Burke Museum, University of Washington.

Jepson Manual
The Jepson Manual: Vascular Plants of California. B.G. Baldwin, D.H. Goldman, D.J. Keil, R. Patterson, T.J. Rosatti, and D.H. Wilken [editors]. 2012. 2nd edition, thoroughly revised and expanded. University of California Press, Berkeley, CA. $131.95, hardcover; 1600 pages. ISBN-13: 978-0520253124.