Eriocoma hymenoides (Roem. & Schult.) Rydb.
Viridiplantae > Streptophyta > Streptophytina > Embryophyta > Tracheophyta > Euphyllophyta > Spermatophyta > Magnoliopsida > Mesangiospermae > Liliopsida > Petrosaviidae > commelinids > Poales > Poaceae > BOP clade > Pooideae > Stipodae > Stipeae >Eriocoma > hymenoides [1]
![Eriocoma hymenoides by at Olympus Hill Park, Salt Lake City, UT [2].](/crfs/images/native-plants/plant-directory/indianricegrass-first.jpg)
Eriocoma hymenoides by at Olympus Hill Park, Salt Lake City, UT [2].
Plants growing in dense clumps or tufts (caespitose). Stems (culms) hollow or pithy and hairless and smooth (glabrous) or minutely roughened (scabridulous), 25-70 cm tall, nodes 3-4, sheaths glabrous or scabridulous, sometimes with fine, short hairs (puberulent to pubescent) on end margins. Basal ligules (membranous appendage arising from the inner surface of the leaf junction with the leaf sheath) 1.5-4 mm long, acute, smooth, thin, and translucent; upper ligulesto 2 mm long. Leaf blades usually rolled longitudinally (convolute), 0.1-1 mm in diameter; lower leaf surface glabrous or scabridulous, upper surface pubescent. Panicles (flower clusters) branched, 9-20 cm long and 8-14 cm wide. Branches ascending to spreading, the longest branch 3-15 cm long. Pedicels (stalk of grass spikelet) paired and diverging or spreading apart (divaricate) with the shorter pedicel in each pair at least 1/2 as long as the longer. Glumes (paired bracts at the base of the grass spikelet) subequal, 5-9 mm long by 0.8-2 mm wide, saccate below, tapering above middle with the tips acuminate (gradually tapering to a sharp point and forming concave sides along the tip), bearing short hairs to 0.1 mm long; lower glumes 5-veined basally, 3-veined in the middle; upper glumes 5-7 veined at the base. Individual flowers (florets) 3-4.5 mm long by 1-2 mm thick, inversely egg shaped, with the attachment at the narrower end (obovoid). Lemmas (the lower of the two bracts, the other being the palea, which subtend a grass floret) hardened and densely covered in long, soft, and straight hairs. Calluses (thickened basal extension of the lemma) 0.4-1 mm and sharp. Lemma hairs are 2.5-6mm and easily rubbed off while the apices are not lobed. Awns (the narrow, bristlelike appendage) 3-6 mm long, falling easily (caducous), not geniculate (bearing knee-like bends and joints). Paleas subequal to lemmas in length and texture, glabrous, with apices pinched. Anthers 1.5-2 mm long, penicillate (with tuft-like or soft hairs), and dehiscent (opening at maturity). Caryopses 2-3 mm. Roots not rhizomatous [3].
![Indian ricegrass plant located in Moab [4].](/crfs/images/native-plants/plant-directory/indianricegrass-sec.jpg)
Indian ricegrass plant located in Moab [4].
You can find 3-4 quite prominent nodes on each of their culms (stems). These are hard to miss, and these plants usually have dozens of culms creating a cloud of seeds [3].
The taxonomic history of Eriocoma hymenoides is complex, with the species recognized as part of a number of genera, including Achnatherum, Stipa, Oryzopsis, Milium, and others. However in a recent molecular phylogenetic study of the Stipeae tribe, it was recognized that the taxon is best placed in genus Eriocoma as Eriocoma hymenoides [6].
![Indian ricegrass growing in cryptobiotic crust at White Sands National Monument [5].](/crfs/images/native-plants/plant-directory/indianricegrass-identification1.jpg)
Indian ricegrass growing in cryptobiotic crust at White Sands National Monument [5].
![Eriocoma hymenoides in the Bonneville Terrace foothills of Salt Lake County [8].](/crfs/images/native-plants/plant-directory/fremont-cottonwood-third.jpg)
Eriocoma hymenoides in the Bonneville Terrace foothills of Salt Lake County [8].
Indian ricegrass is valuable to livestock and wild game of all varieties, providing good foraging during the winter months [5]. The seeds of this plant, while used by many animals, were also used historically by Native American tribes who would mash up the seeds to create all sorts of food like flour, cakes, and tortillas [9]. In Nevada, the Paiute tribe ground the seeds to make porridge and soup. They also would use the seeds to treat stomach ailments, colic, and aching bones [10].
![County level range distribution of E. hymenoides [11].](/crfs/images/native-plants/plant-directory/fremont-cottonwood-fourth.jpg)
County level range distribution of E. hymenoides [11].
Being a widely adapted grass species, Indian Ricegrass conservation status is secure [12]. It is considered a key species on Utah foothills and semi-desert range [6].
Well-drained, dry soils, primarily in the western United States, hot and dry exposure, extremely hardy and can survive with little rain fall [7]. The plant can also stabilize shifting sand [13].
[1] Schoch CL, et al. NCBI Taxonomy: a comprehensive update on curation, resources and tools. Database (Oxford). 2020: baaa062. PubMed: 32761142 PMC: PMC7408187
[2] Frates, T. (n.d.). Indian ricegrass (Achnatherum hymenoides). iNaturalist. https://www.inaturalist.org/taxa/117413-Achnatherum-hymenoides/p>
[3] Barkworth, M. E. (2007). Flora of North America (Vol. 24). Oxford University Press. http://floranorthamerica.org/Achnatherum_hymenoides
[4] Alexander , P. (2006). Achnatherum hymenoides, south of Moab in Hidden Valley. photograph, Grand County, UT. https://commons.wikimedia.org/wiki/File:Achnatherum_hymenoides-5-19-05.jpg
[5] (2008). Indian ricegrass growing in cryptobiotic crust at the White Sands National Monument. photograph, White Sands National Park, NM. https://commons.wikimedia.org/wiki/File:White_Sands_vegetation_in_cryptobiotic_crust.jpg
[6] Peterson PM, Romaschenko K, Soreng RJ, Reyna JV. 2019. A key to the North American genera of Stipeae (Poaceae, Pooideae) with descriptions and taxonomic names for species of Eriocoma, Neotrinia, Oloptum, and five new genera: Barkworthia, ×Eriosella, Pseudoeriocoma, Ptilagrostiella, and Thorneochloa. PhytoKeys 126: 89-125. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6650443/
[7] Pratt, M. S. (n.d.). Range plants of Utah. Desert Princesplume. Retrieved September 29, 2022, from https://extension.usu.edu/rangeplants/grasses-and-grasslikes/indian-ricegrass
[8]Frates, T. (2011). Indian Ricegrass at the western base of Mt. Olympus. photograph, Wasatch foothills, Salt lake County, Utah. https://www.flickr.com/photos/54551481@N08/6038980883
[9] Buskirk, Winfred, 1986, The Western Apache: Living With the Land Before 1950, Norman. University of Oklahoma Press, page 189
[10] Fowler, Catherine S., 1989, Willards Z. Park's Ethnographic Notes on the Northern Paiute of Western Nevada 1933-1940, Salt Lake City. University of Utah Press, page 46
[11] USDA, NRCS. 2022. The PLANTS Database (http://plants.usda.gov, 09/28/2022). National Plant Data Team, Greensboro, NC USA.
[12] Indian Mountain-ricegrass. NatureServe Explorer 2.0. (2023a, December 1). https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.147260/Achnatherum_hymenoides
[13] Fagan, Damian (2012). Canyon Country Wildflowers, 2nd ed., Morris Bush Publishing in cooperation with Canyonlands Natural History Association, ISBN 978-0-7627-7013-7, p. 151.
