northern panicgrass
Dichanthelium boreale (Nash) Freckmann

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Northern panicgrass is rare in Iowa, where it is occasionally found in prairies and wet meadows, often in sandy spots, in the northeastern corner of the state. In North America, this species occurs from Newfoundland and Ontario to New York, Vermont, and west across the Great Lakes region to Minnesota and Iowa. Like other species of Dichanthelium, northern panicgrass is characterized by two distinct blooming periods. The conspicuous primary flowering heads are terminal to the culms and are produced from May into June, early in the season. Later on, usually from late June into October, the plants branch, sometimes profusely, to produce small secondary flowering heads in the 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.

Northern panicgrass is distinguished by its delicate culms (no more than 1 mm thick) with smooth nodes and relatively small, hairy spikelets (1.7-2.1 mm long). Northern panicgrass is most similar to forked panicgrass (Dichanthelium dichotomum), a species of the southeastern U.S. that has not been found in Iowa. Forked panicgrass has smooth spikelets, or if they are hairy, the nodes are also hairy. Northern panicgrass occasionally hybridizes with hairy panicgrass (Dichanthelium acuminatum).

Etymology: Dichanthelium from the Greek di = twice and anth = flowering, referring to the occurrence of two distinct flowering periods; boreale from the Latin borealis = northern, referring to primary distribution of these plants in southern Canada and the northeastern United States.

 

Plants perennial, tufted. Culms 24-60 cm, erect or ascending; nodes and internodes smooth. Fall phase with decumbent culms, the branches arising from the lower and middle nodes, rebranching 2-3 times. Basal rosettes well differentiated. Leaves along the culms with sheaths shorter than the internodes, the lower sheaths hairy, the upper sheaths smooth, the margins of all sheaths sparsely ciliate; blades 6-8 cm long, 4-9 mm wide, thin, spreading, usually smooth the base blunt to rounded, ciliate on the margins. Primary flowering heads terminal, borne above the leaves, 4-7 cm long, (2-) 3-5 cm wide, ovate in outline. Spikelets 1.7-2.1 mm long, 0.8-1 mm wide, ellipsoid, pointed, often reddish, shortly hairy; lower glumes 0.8-1.1 mm long, triangular-ovate; upper florets slightly exceeding the upper glumes, pointed; chromosome number 2n = 18.

 

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