Geum laciniatum Murray - Rough Avens


 

|  back  | forward |

Geum laciniatum - (image 1 of 4)

 

Taxonomy

Family: Rosaceae

Habitat

Fields, meadows, sandy alluvium of flood plains, in moist or somewhat dry soil.

Associates

 

Distribution

Nova Scotia to southern Ontario and MI, south to NJ, western VA, WV, KY, and MO. The var. trichocarpum is chiefly Midwestern.

Morphology

Herbaceous perennial; stem 40-100 cm, hirsute; lower leaves long-petioled, pinnately compound, the segments pinnately lobed and incised; upper leaves trifoliate with cuneate-obovate segments, or merely 3-lobed; pedicels minutely puberulent and densely hirsute, the hairs commonly 1-1.5 mm long; sepals triangular, 4-10 mm; petals white, 3.5-mm, distinctly shorter than the sepals; head of achenes subglobose, 12-18 mm; receptacle glabrous or with a few short bristles; achenes 3-5 mm (excluding style), glabrous (var. laciniatum) or sparsely hairy (var. trichocarpum).

Notes

Flowers May to July

Wetland indicator: FACW

The basal leaves produced early in the season are deeply lobed with narrow segments, however basal leaves produced late in the season often have large terminal lobes similar to those of G. macrophyllum.

Can hybridize with G. urbanum (G. macneillii J.-P. Bernard & R. Gauthier). I recently found this hybrid for the first time in central NY. It has the general appearance of G. laciniatum but with yellow petals and abortive achenes. In addition, while the receptacles of G. laciniatum are mostly glabrous except for some short hairs and a ring of longer hairs at the base, those of G. macneillii have a mix of short and long hairs throughout.

Geum macneillii

Geum laciniatum can also hybridize with G. canadense (Geum cortlandicum M. Hough). These hybrids differ from G. laciniatum in having slightly wider petals, fewer stigmas, achenes that are less numerous (92-188) with some short hairs and sometimes some small stalked glands, and like G. macneillii the receptacle has a mix of short and long hairs throughout. The leaves look more like those of G. canadense, often darker green with fewer hairs and sharper marginal teeth.

Geum cortlandicum M. Hough

References

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second Ed.
The New York Botanical Garden. Bronx, NY

 

Hough, M. 2018. Geum cortlandicum (Rosaceae), a new natural hybrid plus three Geum urbanum hybrids new to the flora of New York. Phytoneuron 2018-59: 19.

 


Home

 

 Michael Hough 2018