long-stalked panicgrass
Dichanthelium perlongum (Nash) Freckmann

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Long-stalked panicgrass occurs in the north-central United States and is fairly common in the eastern two-thirds of Iowa, growing in small tufts among other grasses on dry, gravelly upland prairies and sandy river terraces. Like other species of Dichanthelium, long-stalked panicgrass is characterized by two distinct blooming periods. The conspicuous primary flowering heads are terminal to the culms and are produced in June, early in the season. Later on, usually from late June through July (and rarely later), the plants branch profusely to produce small secondary flowering heads in the basal leaf axils. The primary flowering heads usually have a lower seed set than the secondary ones, which have flowers that remain closed and are self-pollinated.

Dichantheliums normally produce a basal rosette of leaves that persists through the winter, remaining green. In long-stalked panicgrass and the other three species that it is most closely related to, the basal rosette is usually only poorly developed. In addition, these four species share narrow leaf blades (usually at least 20 times longer than wide). Long-stalked panicgrass is distinguished from the other linear-leaved dichantheliums, though, by its more or less narrow flowering heads held above the leaves and more or less obovoid spikelets 2.8-3.2 mm long lacking the beak characteristic of starved panicgrass. In addition, the secondary (fall) flowering heads are all basal in this species. Long-stalked panicgrass appears to hybridize occasionally with starved panicgrass (Dichanthelium depauperatum) and linear-leaved panicgrass (Dicanthelium linearifolium).

Etymology: Dichanthelium from the Greek di = twice and anth = flowering, referring to the occurrence of two distinct flowering periods; perlongum from the Latin per = extra or very and longus = long or extended, referring to the long-stalked flowering heads.

 

Plants perennial, densely tufted. Culms 15-45 cm, erect, the lower 3-6 internodes telescoped together, the upper 2 internodes elongated; nodes hairy. Fall phase with sterile branches arising near ground level and foreshortened fertile branches arising from the higher nodes. Basal rosettes poorly developed. Leaves along the culms with sheaths long hairy; blades 5-30 cm long, 2-4 mm wide, stiffly erect, long-tapering, sometimes the edges inrolled, green or grayish green, smooth on the upper surface or both surfaces long hairy. Primary flowering heads terminal, long-exserted, 3-6.5 cm long, 1-3 cm wide, narrowly ellipsoid. Spikelets 2.8-3.2 mm long, 1.5-1.7 mm wide, ellipsoid-obovoid, finely short hairy; lower glume 1-1.5 mm, broadly triangular; upper glume and lower lemma 2.4-2.8 mm long, exceeding the shiny upper floret by 0.2-0.3 mm before flowering but not forming a beak, slightly pointed at maturity. Chromosome number 2n = 18.

 

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