Polanisia dodecandra subsp. trachysperma

(Torrey & A. Gray) H. H. Iltis

Rhodora 68: 47. 1966.

Common names: Sandyseed or western clammyweed
Weedy
Basionym: Polanisia trachysperma Torrey & A. Gray Fl. N. Amer. 1: 669. 1840
Treatment appears in FNA Volume 7. Treatment on page 203. Mentioned on page 202.

Leaflets: blade apex acute to obtuse. Inflorescence bracts lanceolate to ovate. Petals white, (7–)8–13(–16) mm. Stamens (6–)12–28(–40) mm, longest ones ca. 2 or more times as long as petals. Seeds roughened. 2n = 20.


Phenology: Flowering summer–early fall.
Habitat: Gravelly or sandy, sunny places along streams, sandy places, open woodlands, grasslands, roadsides
Elevation: 100-1500(-2100) m

Distribution

V7 263-distribution-map.gif

Alta., Man., Ont., Sask., Ala., Ariz., Ark., Calif., Colo., Conn., Idaho, Ill., Iowa, Kans., Ky., La., Md., Mass., Mich., Minn., Mo., Nebr., Nev., N.Mex., N.Dak., Ohio, Okla., Pa., S.Dak., Tex., Utah, Va., Wash., W.Va., Wyo., Mexico.

Discussion

Subspecies trachysperma is found mainly in the Great Plains and western states. Populations in the eastern United States are presumably adventive, as are those in eastern Ontario, where it has been found spreading in disturbed areas, such as quarries and roadsides (B. McBride 2006).

Selected References

None.

Lower Taxa

None.
Gordon C. Tucker +
(Torrey & A. Gray) H. H. Iltis +
Polanisia trachysperma +
Sandyseed or western clammyweed +
Alta. +, Man. +, Ont. +, Sask. +, Ala. +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Idaho +, Ill. +, Iowa +, Kans. +, Ky. +, La. +, Md. +, Mass. +, Mich. +, Minn. +, Mo. +, Nebr. +, Nev. +, N.Mex. +, N.Dak. +, Ohio +, Okla. +, Pa. +, S.Dak. +, Tex. +, Utah +, Va. +, Wash. +, W.Va. +, Wyo. +  and Mexico. +
100-1500(-2100) m +
Gravelly or sandy, sunny places along streams, sandy places, open woodlands, grasslands, roadsides +
Flowering summer–early fall. +
Cristatella +
Polanisia dodecandra subsp. trachysperma +
Polanisia dodecandra +
subspecies +