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northern yellow-eyed-grass, xyris de montagne, xyris des montagnes

tall yelloweyed grass

Habit Herbs, perennial, cespitose, 5–30 cm. Herbs, perennial, cespitose, occasionally solitary, 2–8(–10) cm, base bulbous.
Stems

compact.

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.

erect or ascending, 15–30(–50) cm;

sheaths pinkish to red, soft;

blade green, linear, flattened, twisted, 5–10 mm wide, smooth, margins smooth.

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 exceeded by leaves;

scapes linear, often flexuous, terete, to (1.5–)2(–3) mm wide, distally 2–4(–6) ribbed, ribs smooth or papillate;

spikes ovoid to cylindric, 8–30 mm;

fertile bracts 5–7 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, light brown, slightly curved, 5–7 mm, keel scarious, lacerate;

petals, unfolding at midday, blade broadly obovate, 5 mm;

staminodes bearded.

Seeds

translucent, narrowly ellipsoid, (0.6–)0.7–0.9(–1) mm, finely lined.

translucent, ellipsoid, 0.5–0.6 mm, longitudinally irregularly ribbed, with fainter cross lines.

2n

= 18.

Xyris montana

Xyris platylepis

Phenology Flowering summer–fall. Flowering summer–fall (all year south).
Habitat Sphagnous bogs, poor fens, acid seeps, shores of glacial lakes, streams, muskegs, or floating bog mats Moist to wet acid, sandy seeps, bogs, low pine flatwoods, savannas, and ditch banks
Elevation 0–500 m (0–1600 ft) 0–300 m (0–1000 ft)
Distribution
from FNA
CT; MA; ME; MI; MN; NH; NJ; NY; PA; RI; VT; WI; NB; NF; NS; ON; QC
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[BONAP county map]
from FNA
AL; FL; GA; LA; MS; NC; SC; TX; VA
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[BONAP county map]
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 platylepis, which may be associated with other bulbous-based species such as X. torta and X. caroliniana, appears very similar to larger extremes of the former but differs in its plane (rather than prominently ribbed) leaf surfaces and its lacerate (rather than ciliate) sepal keels, and from the latter in its more shallowly set and pinkish or red (rather than chestnut brown) bases, as well as in its sepal keels that are lacerate rather than fimbriate.

(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
X. ambigua, X. baldwiniana, X. brevifolia, X. caroliniana, X. difformis, X. drummondii, X. elliottii, X. fimbriata, X. flabelliformis, X. isoetifolia, X. jupicai, X. laxifolia, X. longisepala, X. platylepis, X. scabrifolia, X. serotina, X. smalliana, X. stricta, X. tennesseensis, X. torta
X. ambigua, X. baldwiniana, X. brevifolia, X. caroliniana, X. difformis, X. drummondii, X. elliottii, X. fimbriata, X. flabelliformis, X. isoetifolia, X. jupicai, X. laxifolia, X. longisepala, X. montana, X. scabrifolia, X. serotina, X. smalliana, X. stricta, X. tennesseensis, X. torta
Synonyms X. flexuosa var. pusilla, X. papillosa
Name authority Ries: Bulletin of the Torrey Botanical Club 19: 38. (1892) Chapman: Fl. South. U.S. 501. (1860)
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