3. Competition: The species occurs on sparsely vegetated 

 slopes with a loose surface layer, and does not extend into 

 adjacent grasslands with greater cover. At one locale pine 

 forest is above and savannah below, neither with P. 

 brassicoides . This suggests that the species prefers the less 

 competitive sites where infiltration in the coarse soil is 

 greater than in clay or shale sites. 



4. Herbivory: The steep habitat and sparse vegetative cover 

 is not conducive to grazing, and the slope is too steep for 

 developed cattle trails. The species is also probably 

 unpalatable, and no grazing by rodents or rabbits was 

 observed. 



F. Assessment and management recommendations: While there are no 

 immediate threats, the District contains the only two small 

 populations known in the state. Roadwork potentially affects one 

 of the two populations. Further review of this species as a watch 

 species by Custer National Forest is recommended. 



Sphenopholis obtusata (Michx) Scribn. var. major (Torr.) Erdm. 



Poaceae 

 Slender wedgegrass 

 A. Description 



1. General description: Herbaceous annual or short-lived 

 perennial grass, with a slender nodding spike at the top of 

 the 0.2-1 m (7.9-39.4 in) stem. It is two-flowered and the 

 seeds drop with the glumes. The shape and difference in width 

 of the two glumes is distinctive, the large second being very 

 broad at the upper end like the shape of a wedge, hence the 

 common name. It matures in July and August. 



2. Technical description: Tufted to solitary-stemmed annual 

 or perennial, 2-9.2 (13) dm tall. Culms glabrous, hollow, 

 erect to geniculate below. Blades rolled in the bud, flat at 

 maturity, scabrous to pubescent, mostly 5-20 cm long, 1.5-5.7 

 mm wide; sheaths open, glabrous to scabrous or pubescent; 

 ligules membranaceous, usually lacerate, 1-3 mm long; auricles 

 lacking. Infloresence a moderately open to strongly condensed 

 erect to nodding panicle 4-21 cm long; spikelets usually with 

 2 florets, the rachilla prolonged beyond the upper floret, the 

 disarticulation ultimately below the glumes, but 

 disarticulation of the upper floret often preceding the fall 

 of the entire spikelet; glumes usually scabrous, unlike, the 

 first very narrow, 1-nerved, 1-2.4 mm long, the second 3(5)- 

 nerved, obovate, truncate to obtuse or acute-tipped, 1.5-2.9 

 mm long; lemmas obscurely nerved, smooth to scabrous, the 

 lower one 1.5-2.1 mm long; palea equal to the lemma. Anthers 

 0.2-0.7 mm long (from Great Plains Flora Association 1986). 



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