Cyperus pennatiformis var. pennatiformis

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Monocots Order: Poales Family: Cyperaceae Genus: Cyperus

cyperus

Description

Key Characters:

Growth Form: Perennials with short, ligneous rhizomes clothed with brown scales and their fibrous remnants.

Stems: culms 40–120 cm tall, 3–7 mm in diameter in lower part, acutely trigonous, the sides slightly concave, smooth.

Roots:

Leaves: Leaves simple. 3–5 per culm. Blades subcoriaceous, flat, linear, as long as to slightly longer than the culm, 8–17 mm wide,. Lower surfaces finely septate–nodulose. Margins entire. Sheaths brown to reddish brown, eventually splitting into fine parallel fibers. Stipules absent.

Flowers: Flowers in inflorescences umbelliform, moderately dense, 4–15 cm long, 5–25 cm wide, rays 5– 18, spreading, 2–15 cm long, unbranched or once branched, spikes cylindrical to oblong–ellipsoid, 2–6 cm long, 1.5–2.7 cm wide, densely bearing numerous spikelets; involucral bracts 5–9, longer than the inflorescence, lower ones up to 35 cm long and 22 mm wide; spikelets yellowish brown or grayish brown, 15–24–flowered, spreading to reflexed, flattened, slightly turgid, narrowly oblong to oblong-lanceolate, 10–14 (–20) mm long, 1.7–3.5 mm wide, apex subacute, rachilla narrowly winged, jointed at base; glumes yellowish–brown, chartaceous with membranous margins, closely imbricate, oblong–ovate, 4–5.5 mm long, 2–2.5 mm wide, finely 4–nerved on each side of midnerve, the midnerve prolonged into a short mucro. Flowers bisexual (perfect). Corolla (petals) absent. Ovary superior.

Fruit: Achenes oblong; trigonous; 2 mm long. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy:

Habitat: Found in grasslands; and open sites including ridges and mesic forest.

Elevation Range: 0–1,200 m.

Historical Distribution

Uses and Culture

USES

Natural History

Statewide Status

Endemic

Island Status

Kaua'i Endemic
O'ahu Endemic
Maui Endemic
Hawai'i Not in flora

Dispersal Agents


Pollinators

Bibliography

Other References

Wagner et al. 1990:1421 (K, O, M, H [as Mariscus pennatiformis subsp. pennatiformis]); Tucker 1994:87/Wagner & Herbst 1999:1900 (Syn. M. p. subsp. pennatiformis = C. p. var. pennatiformis); Faccenda, Arthur, et al. 2025:171 (remove H [no evidence of presence]); Matt Keir pers. comm. 2025/Wood 6965 BISH (K†, 1997); MacDaniels 575 BISH (O†, 1927)

Occurrences

SNo. Scientific Name Locality Habitat Basis of Record Description Recorded By Record Number Island Source Date
1 Cyperus pennatiformis var. pennatiformis Locality redacted. Contact Bishop Museum Botany Department for details Preserved_Specimen MacDaniels, L.H. 575 Oahu BISH 1927-01-31
2 Cyperus pennatiformis var. pennatiformis Locality redacted. Contact Bishop Museum Botany Department for details Open rainy region. Preserved_Specimen Degener, O. 8397 Maui BISH 1927-07-19
3 Cyperus pennatiformis var. pennatiformis Locality redacted. Contact Bishop Museum Botany Department for details NW facing slopes of ridge and gulch; Diospyros sandwicensis, Dodonaea viscosa, Acacia koa, Metrosideros, Pleomele aurea, Psychotria greenwelliae, P. mariniana, Nestegis sandwicensis Preserved_Specimen terrestrial with thick rhizomes, culms trigonous, glumes light brown Wood, K.R. 6965 Kauai BISH 1997-11-14
4 Cyperus pennatiformis var. pennatiformis Locality redacted. Contact Bishop Museum Botany Department for details Rather dry open situtation. Preserved_Specimen MacDaniels, L.H. 794 Kauai BISH 1927-02-18
5 Cyperus pennatiformis var. pennatiformis Locality redacted. Contact Bishop Museum Botany Department for details Within reach of ocean spray. Preserved_Specimen Davis, J. 31 Maui BISH 1978-07-03
6 Cyperus pennatiformis var. pennatiformis Locality redacted. Contact Bishop Museum Botany Department for details One hundred eighteen mature plants and estimated 50 immature plants including seedlings observed along 500m of shoreline, on cliffs and among boulders at waters edge. Vegetation: Pandanus, Hbiscus, Ardisia, Cocos, Pluchea, Hedychium, Solanum, Sphagneticola, Aleurites, Begonia, Carex, Lysimachia, Bacopa, Sadleria, Cyrtomium, Adiantum, Ficus, Dioscorea, Hoya, Ipomoea, Digitaria, Ischaemum, Lycium, Spathodea. Preserved_Specimen Culms to 200cm tall, considerably larger than the description of this taxon. Oppenheimer, H.L. 81301 Maui BISH 2013-08-01