- Scientific name: Dichanthelium scoparium (Lam.) Gould
- Species of Greatest Conservation Need (MA State Wildlife Action Plan)
- Endangered (MA Endangered Species Act)
Description
The inflorescence of velvet rosette-grass.
Grasses are a challenging group of plants to identify and often require the use of a technical field guide called a dichotomous key. Velvet rosette-grass is a robust perennial grass which reaches heights of up to 150 cm (59 in). It spreads by rhizomes and can form dense colonies. It forms basal rosettes with lanceolate leaves sometimes exceeding 10 cm (~4 in). These rosettes produce stems with 7-11 leaves measuring 9-20 cm (3.5-7.9 in) long and 9-20 mm (0.35-0.79 in) wide. True to its name, velvet rosette-grass produces dense viscid hairs on its stems, upper leaf surfaces, and the leaf sheath (portion of leaves which clasps the stem). Velvet rosette-grass produces numerous spikelets densely arranged in a panicle which measures 6-16 cm (2.4-6.3 in) long by 5-12 cm (2-4.7 in) wide. Like many grasses, its flowers are small, measuring 2.2-2.8 mm long (0.09-0.11 in) and 1.3-1.5 mm wide (0.05-0.06 in), and inconspicuous, being concealed by a series of specialized structures, including two glumes, a palea, and a lemma. (Freckman and LeLong 2003).
In Massachusetts, velvet rosette-grass is most likely to be confused with other members of the genus Dichanthelium, particularly deer tongue grass (Dichanthelium clandestinum). These two species are the most robust members of the genus in the state, reach similar sizes, and are most readily differentiated by their pubescence. The hairs of deer tongue grass are stiff and arise from tiny bumps called pustules, whereas the hairs of velvety panic-grass are soft and lack pustules at their base.
Velvet rosette-grass in early September.
Life cycle and behavior
Velvet rosette-grass is an herbaceous perennial that produces two kinds of flowers, ones which are wind-pollinated, and produced at the tip of the stem in June or July, and ones which are self-pollinated, and produced at the inner base of upper stem leaves in August. Each flower contains a single seed which is dispersed in late summer.
Population status
Velvet rosette-grass has recently been elevated from state historic to endangered under the Massachusetts Endangered Species Act. Historically, velvet rosette-grass was known from 6 sites in New England all within Massachusetts along the coast (Weise et al 2021). Currently, 3 populations are known from Barnstable, Franklin, and Dukes County. If you see any rare species, please report them through Heritage Hub.
Distribution in Massachusetts
1999-2024
Based on records in the Natural Heritage Database
Distribution and abundance
Velvet rosette-grass is present throughout eastern North America, common from Texas east to north Florida and rare north of New Jersey to Massachusetts (iNaturalist 2025). It is of conservation concern in several states, including critically imperiled in Illinois, Indiana, New York, Ohio, Pennsylvania, West Virginia, and Massachusetts, and imperiled in Kansas (NatureServe Explorer 2025).
Habitat
In Massachusetts velvet rosette-grass inhabits the edges of pond shores, wetland edges and clearings particularly on sandy soils with patterns of disturbance such as fire, mowing, or other control of woody vegetation, especially with periodic soil scarification. These habitats occur throughout most of Massachusetts, especially in coastal areas and inland glacial outwash zones. Fires may have once played a role in maintaining the habitat of velvet rosette-grass.
Healthy habitats are vital for supporting native wildlife and plants. Explore habitats and learn about conservation and restoration in Massachusetts.
Velvet rosette-grass growing along the edge of an access road in an early successional plant community.
Threats
Threats to populations of velvet rosette-grass include succession-related competition by woody plant species. Relatedly, fire suppression, which plays a role in maintaining early sucessional plant communities, is thought to have contributed to a decline in suitable habitat for velvet rosette-grass. By far the largest population of this grass is very close to the seashore in a relatively flat and low landscape, making this population extremely vulnerable to sea level rise. In the Northeast US, sea level has risen about 12 inches since the year 1900, faster than the rate around the world (Staudinger et al. 2024).
Conservation
More survey work is needed as several populations have recently been discovered which means that there are likely more out there to be discovered. Monitoring populations is essential to make sure plant populations are not overgrown with invasive species, brush, wild grape or similar vegetation. Management is also essential to clear brush and trees around these plants to give them more room to grow. Prescribed fire is likely a helpful tool in improving the habitat conditions. Much more research is needed to determine optimal conditions for plant growth and reproduction, seed germination and survival of ex situ plantings.
Acknowledgements
MassWildlife acknowledges the expertise of Matt Charpentier, who contributed substantially to the development of this fact sheet.
References
Freckmann, R.W. and M. G. Lelong. 2003. Dichanthelium (Hitch. & Chase) Gould, pp. 406–450. In: Flora of North America Editorial Committee, M.E. Barkworth, K. M. Capels, S. Long, and M. B. Piep, eds., Flora of North America North of Mexico, vol. 25, Magnoliophyta: Commelinidae (in part): Poaceae, part 2. Oxford University Press, New York, NY.
Haines A (2011) New England Wild Flower Society’s Flora Novae Angliae: a manual for the identification of native and naturalized higher vascular plants of New England. Yale University Press. 1008 pp.
iNaturalist 2025. Available from https://www.inaturalist.org. Accessed 28 March 2025
NatureServe. 2025. NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available https://explorer.natureserve.org/. Accessed: 3/19/2025
Staudinger, M.D., A.V. Karmalkar, K. Terwilliger, K. Burgio, A. Lubeck, H. Higgins, T. Rice, T.L. Morelli, A. D'Amato. 2024. A regional synthesis of climate data to inform the 2025 State Wildlife Action Plans in the Northeast U.S. DOI Northeast Climate Adaptation Science Center Cooperator Report. 406 p. https://doi.org/10.21429/t352-9q86
Weise, A. K., P. P. Grima, M. Charpentier, M. Curtin, and G. Palermo. 2021. Rediscoveries of Dichanthelium scoparium (Poaceae) in Southern New England and Evaluation of Past Records from New England and New York. Rhodora 122: 214–233.
Contact
| Date published: | April 14, 2025 |
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