Plants loosely cespitose, with knotty rhizomes to 2 mm
thick. Basal rosettes often poorly differentiated; blades few,
grading into the cauline blades. Culms 20-55 cm, most forming in the
spring, additional culms sometimes produced in the fall; nodes glabrous
or sparsely ascending-pubescent; internodes all elongated, glabrous or
puberulent; fall phase with a few suberect branches from the lower and
midculm nodes, branches not rebranching, blades slightly reduced, secondary
panicles partially exserted. Cauline leaves 3-4; lower sheaths
not overlapping, sometimes pubescent; upper sheaths overlapping, sparsely
to densely pubescent, hairs papillose-based, margins ciliate; ligules
0.3-0.5 mm, membranous, ciliate, cilia longer than the membranous bases; blades
7-17 cm long, 7-23 mm wide, erect, pale yellow-green to bluish-green, glabrous,
with 7-11 prominent major veins and 30-110 minor veins, bases tapered or rounded
to truncate, margins with papillose-based cilia. Panicles 7-14 cm long,
1-5 cm wide, their length usually more than twice their width, narrowly cylindric,
eventually well-exserted, with 9-46 spikelets; branches strongly ascending,
stiff. Spikelets 3.2-4.1 mm long, 1.8-2.2 mm wide, obovoid, turgid, puberulent
to subglabrous, with rounded apices. Lower glumes 1.7-2.2 mm, narrowly
triangular; lower florets staminate; upper florets longer than
the upper glumes, mucronate. 2n = 36.
Dichanthelium xanthophysum usually grows on sandy or
rocky soils in semi-open pine, oak, or aspen woodlands. It extends from eastern
Saskatchewan and northeast Montana to Quebec, New England, and West Virginia.
Plants from Minnesota and western Quebec approach D.
leibergii in having cauline blades narrower than 10 mm, and papillose-based
hairs. Sterile putative hybrids with D. leibergii and D.
boreale are rare; those with D. boreale have been called Panicum