Stipa

Stipa Comata Stipa spartea

Pictured from left to right: Stipa spartea and Stipa comata

This is a genus of cespitose perennials with basal involute leaves and usually drooping panicles. The spikelets are 1-flowered with the glumes acute or acuminate and longer than the lemma bodies. Lemmas are firm or even hardened and usually tightly enclose the palea and caryopsis and with a long twisted and bent awn. As fruits dry, the awns become more and more twisted orienting the seed properly to the soil. Moisture then straightens the awn driving it into the soil for self-planting. The base of the lemma forms a sharp pointed callus, covered with stiff hairs, that frequently gets caught in passing trousers, socks, and fur. The species are often important components of their grassland types. Several of the species hybridize and some hybridize with the closely related Oryzopsis.

There are 3 species in MN; 3 are native.

Common species:
Stipa spartea (sty' pah spar tee' ah)

  • Synonyms: None
  • Common names: porcupine grass; Lakota: micapeca
  • Origin and habitat: Native; dry prairies and in open, often sandy woods
  • Identifying characters: This species is up to 1 m tall with leafy wispy-looking stems. Leaves are pubescent on the margins in the collar area and sheaths are distinctly wider than the blades; the lower surface is often shiny early in the spring. Ligules are 1-5 mm long and longer on the sides. Lemmas are pubescent and taper into awns 12-20 cm long.
  • Comments: Porcupine grass is another cool-season native with rapid spring growth but forms rather open populations. As the fruits dry, the persistent awns twist and turn driving the seed into the ground (self-sowing). Bundles of fruits were sometimes used as hair brushes by various tribes of American Indians. Porcupine grass can provide valuable forage but only when immature; the sharp base of the mature fruit will become embedded in the mouth of livestock and cause severe discomfort.

Maps
Stipa Comata mapStipa spartea map   

Additional species in Minnesota:
Stipa comata
Stipa viridula

Copyright 2002, A.F. Cholewa, J.F. Bell Museum of Natural History, University of Minnesota / No portion of this guide may be duplicated without written permission of author.