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Xyris platylepis

Chapm. (1860)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Monocots Order: Poales Family: Xyridaceae Genus: Xyris

yellow-eyed grass

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Description

Key Characters:

Growth Form: Perennial herbs, solitary or in small clumps, perennating by pale, fleshy, lateral buds.

Stems: Rhizomes.

Roots: Fibrous root system.

Leaves: Leaves simple. Alternate, equitant. Blades linear, fleshy, twisted and flexuous, 20–40(–50) cm long, 5–10 mm wide. Apex acuminate. Base dilated near base. Surfaces glabrous. Margins minutely scabrous or smooth. Veins parallel. Sheathing, sheaths open. Stipules absent.

Flowers: Flowers on terminal scapes 5–11 dm long, twisted and flexuous, ribs smooth, spikes ellipsoid to ovoid or oblong, 15–30(–40) mm long, 8–15 mm in diameter, bracts subtending each flower broadly elliptic–obovate, 5–7 mm long. Flowers odorless and without nectar, pollinated by bees, bisexual (perfect). Calyx zygomorphic; sepals unequal, the middle one larger, hood-like, caducous, the lateral ones boat-shaped to spatulate, margins often ciliate; lateral sepals 5–6 mm long, keel narrow, entire below, fimbriate above middle. Corolla of 3 petals, yellow or white, opening in the afternoon, broadly obovate, ca. 5 mm long. Stamens 3(6), opposite the petals; filaments adnate to petals; anthers opening by longitudinal slits. Ovary superior, 3-carpellate; ovules orthotropous. style terminal, unlobed or 3-lobed.

Fruit: Capsules 3-valved; loculicidal. Seeds ellipsoid; translucent; 0.5–0.6 mm long; with 10–12 irregular longitudinal lines and scattered; less conspicuous; vertical lines.

Ploidy: 2n = 18

Habitat: Naturalized in wet muddy areas and on lava.

Elevation Range: ca. 500 m.

Historical Distribution

Images

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Uses and Culture

USES

  • Yes

Natural History

Statewide Status

Naturalized

Island Status

Hawai'i Naturalized

Dispersal Agents


Pollinators

Specimens

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Bibliography

Name Published In: Fl. South. U.S.: 501 (1860)

Other References

Wagner et al. 1990:1615 (H); Faccenda, Arthur, et al. 2025:220 (KEY)

Occurrences

SNo. Scientific Name Locality Habitat Basis of Record Description Recorded By Record Number Island Source Date
1 Xyris platylepis Hawaii Preserved_Specimen Hawaii BISH 1959-07-01
2 Xyris platylepis Hawai'I, Puna District, Pu'u Makaala Natural Area Reserve, area at junction of Stainback Highway and road to Pu'u Akaala on N side of road. Wet forest. With Metrosideros, Cibotium, Cheirodendron, Psychotria, Cyrtandra, and Coprosma. Preserved_Specimen Corolla white, stamens, and style yellow. Wagner, W.L. 6748 Hawaii BISH 1992-08-18
3 Xyris platylepis Above Mt. View In swampy, muddy land. Preserved_Specimen Leaves 53 x 0.8 cm., opposite, equitant, in 1 plane; bulb 5 cm. wide; flowers 7 mm. long, pale-yellow to orange, in heads 2 x 0.8 cm. on stalks 105 cm. (3.5 ft.) long. Yamayoshi, H.T. Hawaii BISH 1959-09-03
4 Xyris platylepis Volcano, Royal Hawaiian Estates, Puolani St. Weedy roadside, sunny, wet. Preserved_Specimen Common, clump forming, no flowers seen at this time. Twisted leaves; base somewhat bulbous and succulent, pinkish on sheaths, floral scales orbicular, coriaceous, seed 0.6 mm, translucent yellowish, with rectangular cells on seed surface; sepals 7 mm, keels lacerate. Faccenda, K. 3271 Hawaii BISH 2024-01-05
5 Xyris platylepis Above Mt. View In swampy, muddy land. Preserved_Specimen Leaves 53 x 0.8 cm., opposite, equitant, in 1 plane; bulb 5 cm. wide; flowers 7 mm. long, pale-yellow to orange, in heads 2 x 0.8 cm. on stalks 105 cm. (3.5 ft.) long. Yamayoshi, H.T. Hawaii BISH 1959-09-03
6 Xyris platylepis Hilo Grown by Japanese nurseryman. Preserved_Specimen Fine, J. Hawaii BISH 1951-02-06
7 Xyris platylepis District of Hilo; Stainback Hwy. ca. 10 mi from junction with Hwy. 11 Common along roadside in this very wet area. Preserved_Specimen Petals pale yellow-white to bright yellow. Flynn, T.W. 1309 Hawaii BISH 1985-10-17
8 Xyris platylepis Between Mountain View and Glenwood, off Mamalahoa Hwy alongside roads 18 to 22 miles Common alongside road. Preserved_Specimen Wentworth, J.O. Hawaii BISH 1962-01-14
9 Xyris platylepis North Peck Rd., NW of Glenwood Common, on marshy ground in old cleared land. Preserved_Specimen Erect, single stems and small tufts, petals white, yellowish at base. Fosberg, F.R. 60541 Hawaii BISH 1980-09-06
10 Xyris platylepis 7 mi SW of State Route 11 on Mamaki Road to Kulani Prison. Waiakea Forest Reserve Preserved_Specimen Herb; corollas yellow. Miller, J.S. 7942 Hawaii BISH 1992-08-06
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