Jimcus covillei Piper 

 Coville's rush 



A. DESCRIPTION 



1. General description: This is a rhizomatous, grass-like rush 

 (Juncaceae) . Rushes are distinguished from other graminoids by 

 having lily-like flowers with six more or less similar 

 perianth parts. J. covillei has flat leaves and its mature 

 capsules are nearly as long or longer than the relatively 

 short perianth. 



2. Technical species description (quoted from Hitchcock et al. 

 1969) : 



Strongly rhizomatous perennial mostly 0.5-2(2.5) dm tall, 

 the stems slightly flattened; leaves flattened, 2 to 4 

 per stem, the blades grasslike, the sheaths with narrow 

 membranous margins that usually project into linear-acute 

 auricles 0.5-1.5 mm long; inflorescence of 1-5(6) 

 discrete heads, sometimes equaled or exceeded by the 

 upper leaves or the foliaceous involucral bract, mostly 

 3- to 7-flowered; perianth 3-4 mm long, pale to deep 

 brown, the segments ovate-oblong, broadly scarious- 

 margined, minutely papillate-roughened, the outer series 

 rounded to acute and short-mucronate, the inner series as 

 long or slightly shorter, rounded or rarely slightly 

 acute but not mucronate; stamens 6, the anthers mostly 1- 

 1.2(0.8-1.4) mm long, from longer to shorter than the 

 filaments; capsule cylindric-ovoid, rounded and usually 

 retuse at the tip, exceeding the perianth by as much as 1 

 mm, usually dark brown; style about 1 mm long; seeds 

 barely 0.3 mm long, obliquely cylindric-ovoid, semi- 

 truncate, but minutely apiculate at each end, faintly 

 reticulate. 



Note: Two varieties of Juncus covillei are present in 

 Montana, J. c. var. covillei and J. c. var. obtusatus . 

 The former is primarily in lowlands and the latter is 

 montane. Most Montana specimens, as with the putative 

 Gallatin National Forest specimen, have not been 

 identified to variety. Both varieties are apparently 

 rare in the state. Annotation to variety is warranted. 



3. Diagnostic characters: The following combination of 

 characters are used to key out J. covillei in Montana (Dorn 

 1984) : Perennial 



Leaf blades flat, not septate 



Heads 3-12 flowered 



Flowers subtended by a single bract, not by a pair of 



bracteoles 

 Perianth segments 2.5-4 mm long, membranous margined 

 Seeds lacking appendages 



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