- Scientific name: Agrimonia pubescens Wallr.
- Species of Greatest Conservation Need (MA State Wildlife Action Plan)
- Threatened (MA Endangered Species Act)
Description
Downy agrimony in flower. Photo credit: Steve Pelikan
Downy agrimony (Agrimonia pubescens) is a perennial herb of woodlands, especially in openings, on ledges, and along trails. It is a member of the rose family (Rosaceae) and has small, yellow flowers, alternate divided leaves, and soft, dense hair throughout.
Downy agrimony grows 30–80 cm (1-2.5 feet) in height. The leaves are pinnately divided and slightly hairy (pubescent) above, densely so below, and velvety to the touch. The stem is densely hairy with hairs 2-3 mm long, and it has no glandular hairs. Each leaf consists of 5 to 7 (rarely 9) toothed, oblong larger leaflets, which are typically opposite each other along the leaf rachis with a terminal leaflet of the same size. Interspersed between the larger leaflets are typically one or two pairs of smaller leaflets. The flowers bloom from July through September, have five yellow petals, and are arranged sub-opposite along a narrow unbranched stalk (raceme). To aid seed dispersal, the cap-like fruits have 3 or 4 rows of hooked bristles that adhere to clothing and fur.
Downy agrimony closely resembles the other four species of agrimony native to Massachusetts. Downy agrimony can be separated from most other species of agrimony by the absence of tiny, stalked glands on the axis (rachis) of the racemes (flowering stalks). Coarse agrimony (Agrimonia striata), a common species which also has no glandular hairs on its rachis, can be distinguished from downy agrimony by its larger fruits which are 4-5 mm (0.16 - 0.2 in) long and the presence of copious glandular dots on the undersurface of the leaves compared to the fruits of downy agrimony that are 2.5-3 mm (0.1 in) long with few to no glandular dots on the leaf undersides. The glandular dots are most visible on dried leaflets.
Downy agrimony plant without flower. Photo credit: Karro Frost
Life cycle and behavior
Downy agrimony is a perennial herbaceous species. Its yellow flowering spikes are visible from the end of June through early August, and mature fruits are present from mid-July through the end of September. The flowers are self-compatible, and it can self-pollinate if outcrossing doesn’t occur. It is necessary to use a hand-lens to determine whether there are glandular hairs on the rachis, shiny glands on the underside of a leaflet, and a metric ruler is recommended to measure fruit lengths. This rare plant has often been confused with similar species and can be difficult to identify.
Population status
Downy agrimony seed. Photo credit: Peter Grima
Downy agrimony is listed under the Massachusetts Endangered Species Act as threatened. All listed species are legally protected from killing, collection, possession, or sale, and from activities that would destroy habitat and thus directly or indirectly cause mortality or disrupt critical behaviors. Downy agrimony is currently known from 12 populations in Berkshire, Dukes, Hampden, Hampshire, and Nantucket counties. It is historically known from Middlesex and Suffolk County. Thirteen populations have not been observed since 2000.
Distribution and abundance
The range of downy agrimony extends from Quebec, Maine, and Massachusetts, west to Ontario and South Dakota, and south to Texas, Louisiana, and Georgia. It is also known to be rare in Delaware, South Carolina, Nebraska, and Quebec. Downy agrimony was historically known from Rhode Island, Vermont, and South Dakota.
Distribution in Massachusetts
1999-2024
Based on records in the Natural Heritage Database
Habitat
Downy agrimony inhabits edges and openings within rich, rocky woodlands on steep slopes or ledges, often over circumneutral or calcareous bedrock. Interestingly, populations are present not only in the marble and traprock regions of the state, but also on Martha’s Vineyard and Nantucket, indicating that this plant is not a strict calciphile. Its affinity for openings suggests that habitat conditions are most favorable with periodic disturbance. Downy agrimony is often associated with a canopy of white ash (Fraxinus americana), sugar maple (Acer saccharum), hop hornbeam (Ostrya virginiana), and hickories (Carya spp.). Associated herbs may include wild strawberry (Fragaria virginiana), white wood-aster (Eurybia divaricata), white avens (Geum canadense), and hog-peanut (Amphicarpaea bracteata).
Healthy habitats are vital for supporting native wildlife and plants. Explore habitats and learn about conservation and restoration in Massachusetts.
Threats
Downy agrimony requires partial sun exposure. Therefore, forest maturation and canopy closure, resulting from a lack of natural or anthropogenic disturbance, often casts too much shade. Invasive exotic plant species may over-shade or out-compete downy agrimony at some sites. Although suitable habitat is apparently available for this species in Massachusetts, it is still quite rare, indicating that there are additional unknown factors influencing its distribution.
Conservation
As with many rare species, the exact management needs of downy agrimony are not known. Sites should be monitored for over-shading caused by forest succession, and for invasive plant species. Habitat sites that do not receive enough light can be managed with canopy thinning or prescribed burning. To avoid inadvertent harm, all active management of rare plant populations (including invasive species removal) should be planned in consultation with the Massachusetts Natural Heritage & Endangered Species Program. The best time for monitoring surveys is later in the summer during flowering or once the fruits have matured.
References
Gleason, Henry A., and Arthur Cronquist. Manual of Vascular Plants of Northeastern United States and Adjacent Canada, Second Edition. Bronx, NY: The New York Botanical Garden, 1991.
Haines, Arthur. Flora Novae Angliae. New England Wild Flower Society, Yale University Press, New Haven, CT. 2011.
Kline, Genevieve J. and Paul D. Sorensen. A revision of Agrimonia (Rosaceae) in North and Central America. Brittonia, 60(1), 2008, pp. 11–33.
NatureServe. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. Accessed: 1/16/2025.
Weakley, A.S. 2020. Flora of the southeastern United States. University of North Carolina Herbarium, North Carolina Botanical Garden
Contact
| Date published: | March 6, 2025 |
|---|