Calamovilfa longifolia (Sand Reed Grass)

Plant Info
Also known as: Prairie Sandreed
Family:Poaceae (Grass)
Life cycle:perennial
Habitat:sun; dry sandy soil; sand prairies, plains, roadsides, railroads, barrens
Fruiting season:August - September
Plant height:4 to 7+ feet
Wetland Indicator Status:none
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information

Flower: Flower shape: indistinct Cluster type: panicle

[photo of spike cluster] Branching cluster at the top of the stem, 6 to 30 inches long, lance-linear in outline, the branches up to 9 inches long and erect to ascending to spreading, with branchlets mostly arranged on the upper half to 2/3 of the branch. Spikelets (flower clusters) are overlapping at the tip of a branchlet but not tightly crowded, and are short-stalked, narrowly lance-elliptic in outline with a single floret.

[close-up of branch and spikelet] At the base of a spikelet is a pair of bracts (glumes) that are thin, papery, narrowly egg-shaped with a pointed tip, initially whitish with a green keel drying whitish to pale brown, the upper glume 5 to 8.2 mm long, the lower glume about ¾ as long. Florets are surrounded by a pair of bracts (lemma and palea), the lemma thin and papery, 3.5 to 7 mm long, awnless, 1-veined, the palea more or less as long. The thickened base of the floret (callus) is densely covered in long, white hairs that are at least half as long as the floret but are all or mostly hidden by the glumes.

Leaves and stems: Leaf attachment: alternate Leaf type: simple

[photo of leaves] Leaves are 12 to 24 inches long, 5 to 12 mm (to ~½ inch) wide, gray-green to blue-green, hairless, mostly floppy, flat towards the base and rolled inward along the edges (involute) above, and gradually tapering to a thread-like tip. Five to 10 leaves are alternately attached along the stem, the lower leaves more crowded than the upper with sheaths overlapping.

[photo of sheath, ligule and node] The sheath is usually hairy along the edge at the tip, with short and/or long white hairs; the surface is hairless or sparsely to densely hairy. The ligule (membrane where the leaf joins the sheath) is a fringe of hairs up to 1 mm long. Nodes are smooth, not much swollen, and often hidden by the sheaths. Stems are hairless, unbranched, mostly erect, usually single, sometimes forming loose clumps. Plants form colonies from long, scaly rhizomes.

Fruit: Fruit type: seed without plume

[photo of individual spikelet and callus hairs] Spikelets are whitish to pale brown at maturity, the florets shedding individually as each grain matures, leaving the glumes behind. Grains (seeds) are light brown, 2.5 to 4.5 mm long.


Sand Reed Grass is a fairly common grass of dry, sandy soils. There are 2 recognized varieties: var. magna with spreading to ascending panicle branches, spikelets overlapping no more than 1 other spikelet, and usually hairy sheaths, is present from Wisconsin to New York, mostly around the Great Lakes; var. longifolia, present from Wisconsin westward, has erect to ascending panicle branches, spikelets overlapping 2 or 3 other spikelets, and usually hairless sheaths except at the tip along the edges. The species in Minnesota, var. longifolia, is distinguished from other grasses with a similar panicle by the single-flowered spikelets, the long hairs around the base of the floret (usually hidden by the glumes), the fringe of hairs for a ligule, and the long floppy leaves becoming thread-like at the tip. Usually a fairly tall grass, the colonies of pale, slender panicles with somewhat silvery foliage tend to stand out.

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • Minnesota Native Landscapes - Your Ecological Problem Solvers
  • Spangle Creek Labs - Native orchids, lab propagated
  • Prairie Restorations - Bringing people together with the land
  • Landscape Alternatives
  • ReWild Native Gardens

More photos

Photos by K. Chayka taken at Moore Lake Dune, Anoka County. Photos courtesy Peter M. Dziuk taken in Anoka, Dakota, Norman, Ramsey and Washington counties.


Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: Jason Osowski - Sherburne County
on: 2021-10-06 20:42:01

Found a few of these plants going to seed in Oak Savanna County Park in Becker, MN. Dry, sandy Savanna edged by open prairie. Mixed in with Indian Grass and Little Bluestem. 9/29/21

Posted by: Doug McEvers - 3 miles NE of Barnesville
on: 2023-03-20 14:41:35

We have Prairie sandreed on our farm 3 miles NE of Barnesville. It has made it's way into the acres we restored in 1993. A bordering prairie remnant has sandreed and it has likely spread from there. It is quite a stately grass and grows on our driest soils. I will be working with a neighbor this year on a 13 acre prairie restoration and I will include a bit of Prairie sandreed seed.

Post a comment

Note: All comments are moderated before posting to keep the riff-raff out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.


Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.