''Calamagrostis tweedyi'', the Cascade reedgrass or Tweedy's reedgrass, is a perennial in the

grass family Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns and ...

. It is native to the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

in the United States, in

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered on ...

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

, and

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

Taxonomy

Cascade reedgrass was first described and published as ''Deyeuxia tweedyi'' in 1883 by

Frank Lamson-Scribner Frank Lamson-Scribner (April 19, 1851 – February 22, 1938) was an American botanist and pioneering plant pathologist. He was the first United States Department of Agriculture scientist hired to study plant disease in economic plants and first USDA ...

, who named it in honor of

Frank Tweedy Frank Tweedy (1854–1937) was an American topographer and botanist. He worked on pioneering surveys first in the Adirondacks, and then in the American West. He also made major contributions to our knowledge of the western flora and vegetation. H ...

, the first to collect it. A fragment of Tweedy's specimen, an alleged isotype, is deposited at the US National Herbarium;''Deyeuxia Tweedyi'' alleged isotype (fragment), US
Search on Catalogue No. 866030 the location of the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

is unknown.''Deyeuxia tweedyi'', Tropicos
/ref> In 1892, Scribner moved Cascade reedgrass to the genus ''Calamagrostis''."Calamagrostis tweedyi" in Flora of North America
/ref> Peterson et al. (2019) recently proposed moving it to the genus ''Greeneochloa'' in their revision of ''Calamagrostis'' based on morphological and molecular evidence. ''G. tweedyi'' would be one of two species in that genus.

Description

''Calamagrostis tweedyi'' is a perennial grass to , typically loosely clumped from short

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

s. Its stem leaves are flat and notably broad, growing to wide and long. Its leaves have open sheaths and membranous

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (Poaceae) and sedges. A ligule is also a strap-shaped extension of the corolla, such as that of a ...

s 6–15 mm long; auricles are absent. The

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

is usually contracted (spike-like), sometimes interrupted at base, up to long and wide. Its

spikelet A spikelet, in botany, describes the typical arrangement of the flowers of grasses, sedges and some other Monocots. Each spikelet has one or more florets. The spikelets are further grouped into panicles or spikes. The part of the spikelet that ...

s consist of two

glume In botany, a glume is a bract (leaf-like structure) below a spikelet in the inflorescence (flower cluster) of grasses (Poaceae) or the flowers of sedges (Cyperaceae). There are two other types of bracts in the spikelets of grasses: the lemma and ...

s roughly equal in size, which enclose and are slightly longer than the single

floret This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...

. The sharply bent

awn AWN may stand for: * Awn Access to Justice Network in Gaza Strip, Legal Aid Network operate in Gaza Strip, Palestine * Animation World Network, an online organization for animators * Avant Window Navigator, a dock-like bar that tracks open windows ...

from the

lemma Lemma may refer to: Language and linguistics * Lemma (morphology), the canonical, dictionary or citation form of a word * Lemma (psycholinguistics), a mental abstraction of a word about to be uttered Science and mathematics * Lemma (botany), a ...

exceeds the glumes by as much as 5 mm, a notable characteristic for this species. The

callus A callus is an area of thickened and sometimes hardened skin that forms as a response to repeated friction, pressure, or other irritation. Since repeated contact is required, calluses are most often found on the feet and hands, but they may o ...

of the floret is only slightly bearded, the hairs short.Cascade reedgrass, Montana Field Guide
/ref> DEYTWEspikelet1882

''Calamagrostis tweedyi'' can be distinguished from other reedgrasses in the region by its flat broad leaves combined with long bent awns and only slightly hairy calluses. Vegetative plants are similar to ''

Cinna latifolia ''Cinna latifolia'' is a species of grass known by the common name drooping woodreed. It is a native bunchgrass to the Northern Hemisphere, where it has a circumboreal distribution. It grows in moist habitat, such as forest understory and riverba ...

'', being stout with broad leaves, and the two sometimes grow in the same habitat.

Distribution

''Calamagrostis tweedyi'' is endemic to the

in the United States, growing in central Washington, Oregon (reported from near Crater Lake), central Idaho, and western Montana.''Calamagrostis tweedyi'' in Burke Herbarium Image Collection
/ref> It grows in montane and subalpine moist meadows and coniferous forests at 900–2000 m elevation.Idaho Native Plant Society newsletter Dec 2017
/ref>

Conservation Status

Due to its restricted (though geographically dispersed) range, relatively few occurrences, lack of protected occurrences, and effects of historic fire exclusion, Cascade reedgrass is ranked G3, globally vulnerable. It is of conservation concern in the states where it occurs.

History

Cascade reedgrass was first collected by

, on the Green River trail in the Cascade Mountains in Washington Territory in 1882. It likely was Tweedy's first novelty (a species new to science). He discovered it during his first season botanizing in the American West, when he was working as a topographer on the Northern Transcontinental Survey. In his description of the new species, Scribner noted: "Mr. Tweedy has been a careful and zealous collector of the plants of the various sections of our country which he has visited, and it is with pleasure that I dedicate this species to him." It would be the first of many named in his honor. Scribner and Tweedy would later coauthor Grasses of Yellowstone National Park, published in 1886.Botanical Gazette 11:169-178; Biodiversity Heritage Library
/ref>

References

{{Taxonbar, from=Q15486981 Perennial plants tweedyi Plants described in 1892