Xyris de montagne

Xyris flexuosa Muhlenberg. var. pusilla A. Gray, Manual ed. 5, 548. 1867; X. papillosa Fassett

Herbs, perennial, cespitose, 5--30 cm. Stems compact. Leaves in narrow fans, 4--15 cm; sheaths reddish, soft, papillate; blade deep green, narrowly linear, 0.8--2(--3) mm wide, smooth, margins smooth to papillate. Inflorescences: scape sheaths exceeded by leaves; scapes linear, wiry, terete, (0.25--)0.5-- 0.8(--1) mm wide, distally with 2--4 ribs, ribs papillate; spikes broadly to narrowly ellipsoid or ovoid, 4--8 mm; fertile bracts 3--4(--4.5) mm, margins erose or minutely fimbriolate, sometimes with narrow reddish border, apex very slightly to slightly keeled. Flowers: lateral sepals slightly exserted, straight, 4.2--4.7 mm, keel scarious, entire or apically lacerate, apex red, narrow, firm; petals unfolding in morning, blade obovate, 3--4 mm; staminodes bearded. Seeds translucent, narrowly ellipsoid, (0.6--)0.7--0.9(--1) mm, finely lined.

Flowering summer--fall. Sphagnous bogs, poor fens, acid seeps, shores of glacial lakes, streams, muskegs, or floating bog mats; 0--500 m; N.B., Nfld. and Labr. (Nfld.), N.S., Ont., Que.; Conn., Maine, Mass., Mich., Minn., N.H., N.J., N.Y., Pa., R.I., VtT., Wis.

Most or all known populations of this species fall within the boundaries of Wisconsin glaciation. The long stems (a trait not known for other North American species) are a response to the burial of the clump bases in deep sphagnum.