Xyris montana |
Xyris ambigua |
|
---|---|---|
northern yellow-eyed-grass, xyris de montagne, xyris des montagnes |
coastal plain yelloweyed grass |
|
Habit | Herbs, perennial, cespitose, 5–30 cm. | Herbs, perennial, cespitose or solitary, 30–100 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. |
in broad or narrow fans, (5–)10–40(–50) cm; sheath base tan, straw-colored, or pale pink; blade pale or olive green, linear-triangular, (2–)3–7(–10) mm wide, smooth or slightly papillate, margins smooth to minutely scabrous or 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. |
scape sheaths much exceeded by leaves; scapes linear, rarely flexuous, terete or nearly terete, 1–1.5 mm wide, distally usually 2-ribbed, sometimes with additional ribs; spikes ovoid to ellipsoid, lanceoloid, or cylindric, 10–20(–30) mm; fertile bracts 5–8 mm, margins entire, apex rounded. |
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. |
lateral sepals included, dark brown, strongly curved, 4–7 mm, keel firm, ciliate, petals unfolding in morning, blade obovate, 10 mm; staminodes bearded. |
Seeds | translucent, narrowly ellipsoid, (0.6–)0.7–0.9(–1) mm, finely lined. |
translucent, ovoid to ellipsoid, 0.5–0.6 mm, finely multiribbed and cross ribbed. |
2n | = 18. |
|
Xyris montana |
Xyris ambigua |
|
Phenology | Flowering summer–fall. | Flowering late spring–fall (all year south). |
Habitat | Sphagnous bogs, poor fens, acid seeps, shores of glacial lakes, streams, muskegs, or floating bog mats | Acid, sandy, moist pine or oak savanna, pine flatwoods, pond shores, ditches, bogs |
Elevation | 0–500 m (0–1600 ft) | 0–300 m (0–1000 ft) |
Distribution |
CT; MA; ME; MI; MN; NH; NJ; NY; PA; RI; VT; WI; NB; NF; NS; ON; QC
|
AL; AR; FL; GA; LA; MS; NC; SC; TN; TX; VA; Mexico; Mexico; West Indies (Cuba); Central America (Belize, Honduras, Nicaragua)
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Discussion | 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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Xyris ambigua is one of the more widespread and weedy of xyrids, frequently invading disturbed moist, sandy areas. It is also one of the most variable in habit and apparently forms intermediates with X. stricta and X. torta. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 22. | FNA vol. 22. |
Parent taxa | Xyridaceae > Xyris | Xyridaceae > Xyris |
Sibling taxa | ||
Synonyms | X. flexuosa var. pusilla, X. papillosa | |
Name authority | Ries: Bulletin of the Torrey Botanical Club 19: 38. (1892) | Beyrich ex Kunth: Enum. Pl. 4: 13. (1843) |
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