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Eleocharis obtusa

(Willd.) Schult. (1824)

This name is accepted

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

blunt spikerush, kohekohe, pīpīwai [pipiwai], spikerush

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Description

Key Characters:

Growth Form: Annuals.

Stems: Culms densely tufted, pale green, slender, 3–40 cm tall, 0.5–1.5 mm in diameter.

Roots:

Leaves: Leaves simple. alternate, basal or nearly so. reduced to bladeless sheaths. Margins entire. Sheaths 1–6 cm long, the lower ones brownish purple, the orifice slightly oblique, margins tinged purplish. Stipules absent.

Flowers: Flowers in spikelets densely many–flowered, ovoid to ovoid–ellipsoid, 5–13 mm long, 3–5 mm wide, obtuse; glumes brown, ovate to elliptic–ovate, 2–2.5 mm long, ca. 1.5 mm wide, obtuse, with a broad hyaline margin, the green midrib ending below the glume apex. Flowers bisexual (perfect). Calyx of 6–7 bristles, brown, retrorsely spinulose, longer than the achene. Corolla (petals) absent. Ovary superior; styles base deltoid, nearly as wide as the achene; stigmas 2–3.

Fruit: Achenes brown; glossy; smooth; obovoid; thickly biconvex with thickened angles; 1–1.5 mm long. Seeds 1; seed coat thin; free from pericarp; embryo basal; endosperm abundant.

Ploidy: 2n = 10

Habitat: Occurring in wet areas; bogs; ponds; and along streams.

Elevation Range: 390–1,900 m.

Historical Distribution

Images

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Uses and Culture

USES

Natural History

Statewide Status

Indigenous

Island Status

Kaua'i Indigenous
O'ahu Indigenous
Molokai Indigenous
Maui Indigenous
Hawai'i Indigenous

Dispersal Agents


Pollinators

Bibliography

Name Published In: Mant. 2: 89 (1824)

Other References

Wagner et al. 1990:1403 (K, O, Mo, M, H)

Occurrences

SNo. Scientific Name Locality Habitat Basis of Record Description Recorded By Record Number Island Source Date
1 Eleocharis obtusa Halii Valley along brook Preserved_Specimen Degener, O. 2202 Kauai BISH 1926-06-11
2 Eleocharis obtusa Alakai Swamp, trail near Kawaikoi Stream muddy Preserved_Specimen Stemmermann, R.L. 7121 Kauai BISH 1986-09-08
3 Eleocharis obtusa Site 04 OS; Piihonua; Hilo Forest Reserve Stunted `ohi`a wetland dieback. Primary vegetation: Meterosideros polymorpha, Acacia koa on well drained hummocks, Ilex anomala, Myrsine lessertiana, Cheirodendron trigynum & Gouldia sp. Soil a moderately deep poorly drained organic. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-06-06
4 Eleocharis obtusa Kokee stream bed, wooded Preserved_Specimen 0.25 m Lee, H.A. 221 Kauai BISH 1925-11-22
5 Eleocharis obtusa East of Humuula, below Kalaieha in pool on pahoehoe Preserved_Specimen Neal, M.C. 697 Hawaii BISH 1935-08-07
6 Eleocharis obtusa Site 02 OS; Piihonua; Hilo Forest Reserve Stunted `ohi`a wetland dieback. Associated spp.: Metrosideros polymorpha, Ilex anomala, Gouldia sp., Pelea clusiifolia, Cheirodendron trigynum, Myrsine lessertiana. Soil a shallow poorly drained organic found over a pahoehoe flow. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-06-05
7 Eleocharis obtusa Site 28 OS; Piihonua; Hilo Forest Reserve Primary vegetation: Metrosideros polymorpha (sometimes pubescent), Ilex anomala, Cheirodendron trigynum, Myrsine lessertiana, Vaccinium calycinum, & Sadleria pallida. Soil a deep moderately well drained ash. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-06-21
8 Eleocharis obtusa Kau Forest Reserve, Mt. House Trail Growing in a small roadside, water-filled depression. Wet, open, grassy area. Preserved_Specimen Herbst, D.R. 194 Hawaii BISH 1966-08-04
9 Eleocharis obtusa Site 25 OS, Piihonua, Hilo Forest Reserve. Stunted ohia wetland dieback. Assoc. spp.: Metrosideros polymorpha, Acacia koa on well drained hummocks, Ilex anomala, Myrsine lessertiana, Cheirodendron trigynum, Pelea spp., Vaccinium calycinum. Soils are moderately deep, yet poorly drained organic cover over a thin ash deposit. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-07-03
10 Eleocharis obtusa Site 09 OS; Hilo Forest Reserve `Ohi`a wetland dieback. Primary vegetation: Metrosideros polymorpha, Acacia koa, Cheirodendron trigynum, Myrsine lessertiana, M. sandwicensis, Ilex anomala, Vaccinium calycinum & Antidesma platyphyllum. Soil shallow & poorly drained. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-06-06
11 Eleocharis obtusa Kohala Mountains: head of Alakahi Gorge Very local in eroded boggy slope where clay is exposed. Preserved_Specimen Tufted. Fosberg, F.R. 41715 Hawaii BISH 1961-03-23
12 Eleocharis obtusa Puna District, land of Olaa; weed along cane field road near North Kulani Road Growing in tufts around and in standing water. Preserved_Specimen Herbst, D.R. 5589 Hawaii BISH 1975-12-15
13 Eleocharis obtusa Pearl City Cultivated potted plant. Preserved_Specimen Purchased from Hui Ku Maoli Ola nursery. Eickhoff, D. Oahu BISH 2009-02-20
14 Eleocharis obtusa Site 25 OS; Piihonua; Hilo Forest Reserve Stunted `ohi`a wetland dieback. Assoc. spp.: Metrosideros polymorpha, Acacia koa on well drained hummocks, Ilex anomala, Myrsine lessertiana, Cheirodendron trigynum, Pelea spp., Vaccinium calycinum. Soil moderately deep yet poorly drained. Preserved_Specimen Adee, K.T. Hawaii BISH 1978-10-23
15 Eleocharis obtusa West Maui, Hanaula, S slope reservoir margin, trail Preserved_Specimen achenes brown Wagner, W.L. 5858 Maui BISH 1988-03-08
16 Eleocharis obtusa East Maui, 3 mi E of Olinda, on road to flume, near reservoir in small pond in 4 of water Preserved_Specimen Henrickson, J.S. 3745 Maui BISH 1969-06-27
17 Eleocharis obtusa Puu Kolekole, Kawela swamp Preserved_Specimen tufts St.John, H. 19884 Molokai BISH 1938-12-30
18 Eleocharis obtusa East Maui, Hana District, vicinity of Kolea Stream Growing in muddy ground, along ditch trail. Preserved_Specimen Oppenheimer, H.L. 100105 Maui BISH 2001-10-14
19 Eleocharis obtusa Paalaa-Wahiawa, Poamoho trail, N summit wet hole Preserved_Specimen Cowan, R.S. 243 Oahu BISH 1946-10-20
20 Eleocharis obtusa Mohihi Stream water, mud Preserved_Specimen 30 cm Bryan Jr., E.H. 1454 Kauai BISH 1940-07-28
21 Eleocharis obtusa Saddle Road, 17.5 miles from Hilo, Waiakea, S. Hilo Dist wet shady stream bed Preserved_Specimen St.John, H. 22418 Hawaii BISH 1946-12-26
22 Eleocharis obtusa Ukulele Pasture above, in a damp erosion gully. Preserved_Specimen Stems rounded, dark green. Forbes, C.N. 974 Maui BISH 1919-07-29
23 Eleocharis obtusa East Maui, Waihoi in standing water with sedges and grasses Preserved_Specimen Harrison, B. 158 Maui BISH 1972-08-04
24 Eleocharis obtusa Wahiawa Bog, W of Reservoir, below Puu Anuka ditch Preserved_Specimen Stone, B.C. 3736 Kauai BISH 1961-08-11
25 Eleocharis obtusa Kipahulu Valley bog; with Carex alligata Preserved_Specimen Nagata, R. Maui BISH 1985-04-30
26 Eleocharis obtusa Site 38 OS; Piihonua; Hilo Forest Reserve `Ohi`a-koa dieback. Associated spp.: Acacia koa, Metrosideros polymorpha, Psidium cattleianum, Cheirodendron trigynum, Antidesma platyphyllum, Vaccinium calycinum, Coprosma sp., Gouldia sp. Soil a deep but somewhat poorly drained ash. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-04-19
27 Eleocharis obtusa Pamoho trail from end of road to jct. with summit, Palaa, Wahiawa, Koolau Range Preserved_Specimen Lamoureux, C.H. 1931 Oahu BISH 1951-10-15
28 Eleocharis obtusa Waimea, Waialae stream near ranger station Preserved_Specimen Skottsberg, C.J.F. 3081 Kauai BISH 1938-08-22
29 Eleocharis obtusa Site 29 OS; Papailou; Hilo Forest Reserve Stunted `ohi`a wetland dieback. Associated spp.: Metrosideros polymorpha, Myrsine lessertiana, Myrsine sandwicensis, Pelea clusiifolia. Soil a thick peaty surface over a poorly drained ash; substrate unknown; water at or near the surface. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-04-06
30 Eleocharis obtusa Kohala Mts, Waimea Preserved_Specimen Forbes, C.N. 512 Hawaii BISH 1911-09-01
31 Eleocharis obtusa Puna District, land of Olaa, volcano transfer dump Preserved_Specimen Tufted sedge Herbst, D.R. 5540 Hawaii BISH 1975-10-23
32 Eleocharis obtusa Proposed Puu Ohu Reservoir, Kohala Mountains Preserved_Specimen Corn, C. Hawaii BISH 1984-03-27
33 Eleocharis obtusa Pahala Preserved_Specimen Height: 1/10 meters, Habit of growth: Clumps Lee, H.A. 177 Hawaii BISH 1926-03-01
34 Eleocharis obtusa Waimea Among ferns Preserved_Specimen Hitchcock, A.S. 14382 Hawaii BISH 1916-08-26
35 Eleocharis obtusa Koolau Mts., Kawailoa FR, summit trail Preserved_Specimen Herbst, D.R. 295 Oahu BISH 1967-01-24
36 Eleocharis obtusa W Waimea drainage basin Preserved_Specimen Forbes, C.N. 868 Kauai BISH 1917-07-03
37 Eleocharis obtusa Olinda along pipeline Preserved_Specimen Hitchcock, A.S. 14893 Maui BISH 1916-10-01
38 Eleocharis obtusa Kalae Preserved_Specimen Forbes, C.N. 53 Molokai BISH 1912-06-01
39 Eleocharis obtusa Waimea, trail from Kokee-Mohihi road to Lehua makanoe Preserved_Specimen Cranwell, L.M. 2932 Kauai BISH 1938-08-15
40 Eleocharis obtusa Hanapepe River, near falls Preserved_Specimen Heller, A.A. 2488 Kauai BISH 1895-07-02
41 Eleocharis obtusa East Maui, Lower Shelf of Kipahulu Valley below Delta Camp Heli Landing Zone. Preserved_Specimen Welton, P. 1638 Maui BISH 1992-06-05
42 Eleocharis obtusa Paauhau No. 2, Parker Ranch Preserved_Specimen Rock, J.F.C. 3353 Hawaii BISH 1909-07-03
43 Eleocharis obtusa East Maui, Makawao Forest Reserve Preserved_Specimen Hobdy, R.W. 1372 Maui BISH 1982-04-30
44 Eleocharis obtusa Poamoho trail, 1/4 mi before summit Preserved_Specimen Davis, J. 11768 Oahu BISH 1977-11-15
45 Eleocharis obtusa Mohihi Stream, trail to intake for ditch Preserved_Specimen Flynn, T.W. 640 Kauai BISH 1983-11-01
46 Eleocharis obtusa Kohala Mts, Kahua Preserved_Specimen Cranwell, L.M. 3445 Hawaii BISH 1938-06-17
47 Eleocharis obtusa Paauhau No. 2, Parker Ranch Preserved_Specimen Rock, J.F.C. 3353 Hawaii BISH 1909-07-03
48 Eleocharis obtusa Kohala Mts. above Waimea (Kamuela) Preserved_Specimen Skottsberg, C.J.F. 715 Hawaii BISH 1922-09-29
49 Eleocharis obtusa Paauhau No. 2, Parker Ranch Preserved_Specimen Rock, J.F.C. 3353 Hawaii BISH 1909-07-03
50 Eleocharis obtusa Kohala Mts, Waimea Preserved_Specimen Forbes, C.N. 512 Hawaii BISH 1911-09-01
51 Eleocharis obtusa Parker Ranch, Paauhau no. 2 Preserved_Specimen Rock, J.F.C. 3352 Hawaii BISH 1909-07-03
52 Eleocharis obtusa Hilo. Preserved_Specimen Rémy, J. 125 Hawaii BISH 1851-01-01
53 Eleocharis obtusa Alakai Swamp, trail between 1st and 2nd bog Preserved_Specimen Herbst, D.R. 2181 Kauai BISH 1971-10-03
54 Eleocharis obtusa Ukulele Preserved_Specimen Forbes, C.N. 983 Maui BISH 1919-07-30
55 Eleocharis obtusa Schofield-Waikane trail, leeward of Koolau Range Preserved_Specimen Crosby, M.R. 1601 Oahu BISH 1964-06-30
56 Eleocharis obtusa W Waimea drainage basin Preserved_Specimen Forbes, C.N. 868 Kauai BISH 1917-07-03
57 Eleocharis obtusa Ukulele Preserved_Specimen Forbes, C.N. 983 Maui BISH 1919-07-30
58 Eleocharis obtusa Alakai Swamp forest Preserved_Specimen Meebold, A. 26370 Kauai BISH 1938-11-01
59 Eleocharis obtusa Honolulu Preserved_Specimen Andersson, N.J. Oahu BISH 1852-01-01
60 Eleocharis obtusa Alakai Swamp Preserved_Specimen Neal, M.C. Kauai BISH 1936-08-17
61 Eleocharis obtusa South Hilo District, Waiakea. Buffer zone collections along Stainback Highway Preserved_Specimen Funk, E.J. Hawaii BISH 1999-04-23
62 Eleocharis obtusa Honolulu Preserved_Specimen Andersson, N.J. Oahu BISH 1852-01-01
63 Eleocharis obtusa Kalihi Taro patches Preserved_Specimen Forbes, C.N. Oahu BISH 1909-06-16
64 Eleocharis obtusa Kalihi Taro patches Preserved_Specimen Forbes, C.N. Oahu BISH 1909-06-16
65 Eleocharis obtusa Keanae Preserved_Specimen Neal, M.C. Maui BISH 1933-06-15
66 Eleocharis obtusa Koolau Range, Puamoho trail, summit Preserved_Specimen Bishop, B. Oahu BISH 1962-04-29
67 Eleocharis obtusa Paauhau no 2, Parker Ranch Preserved_Specimen Rock, J.F.C. Hawaii BISH 1910-07-01
68 Eleocharis obtusa Waimea drainage basin, west side Preserved_Specimen Forbes, C.N. 868 Kauai BISH 1917-07-03
69 Eleocharis obtusa Parker Ranch, Paauhau no. 2 Preserved_Specimen Rock, J.F.C. 3338 Hawaii BISH 1909-07-03
70 Eleocharis obtusa W Waimea drainage basin Preserved_Specimen Forbes, C.N. 1057 Kauai BISH 1917-07-03
71 Eleocharis obtusa [Hawaiian Islands; U.S.A.; Hawaii Preserved_Specimen Hillebrand, W.B. BISH
72 Eleocharis obtusa Koolau Forest Reserve, Kula pipe line, lower flume disturbed Preserved_Specimen Sohmer, S.H. 6660 Maui BISH 1970-08-16
73 Eleocharis obtusa East Maui, Makawao District, Ukulele, above Olinda mud, grassy wet bottoms of shallow ravines on grassy slopes Preserved_Specimen Fosberg, F.R. 51773 Maui BISH 1969-12-11
74 Eleocharis obtusa Kipapa Gulch, Koolau Mts. stream bed Preserved_Specimen Hosaka, E.Y. 1080 Oahu BISH 1933-06-11
75 Eleocharis obtusa Ahualoa, coffee farm irrigation pond Pond dominated by Schoenoplectus mucronatus (70% cover), with Ludwigia palustris, Cuphea carthagenensis, Cyperus halpan, Juncus effusus, Utricularia gibba. Preserved_Specimen Uyehara, K.J. Hawaii BISH 2005-09-24
76 Eleocharis obtusa East Maui, Olinda, Kula pipe line wet trail Preserved_Specimen St.John, H. 10294 Maui BISH 1930-02-11
77 Eleocharis obtusa Ahualoa, Cloud Forest Coffee Farm Seep in wet kikuyu pastureland, submerged to emergent, matlike, forming 100% cover in 10 ft. x 10 ft. area. Preserved_Specimen Uyehara, K.J. Hawaii BISH 2001-05-10
78 Eleocharis obtusa Waimea District. Upper headwaters of the eastern fork of Kawaikoi stream, western Alakai Plateau, Alakai Wilderness Preserve Relatively flat swampy area, on a side rivulet of Kawaikoi stream, in Ohia/Olapa (Metrosideros/Cheirodendron) Wet Forest Paspalum urvillei, Juncus planifolius, Hedychium gardnerianum, Vaccinium calycihum, Cheirodendron platyphyllum subsp. Kauaiensis, Metrosideros polymorpha, Elaeocarpus bifidus. Preserved_Specimen A thick, nearly continuous mat is filling the flat swampy areas around a small side stream of this Kawaikoi headwater. Growing in the dappled shade of trees from the surrounding forest, stems mostly erect, thought area is apparently subject to heavy ungulate traffic, leaving the plants appearing somewhat trampled. Only ___ Williams, A.M. 800 Kauai BISH 2023-06-26
79 Eleocharis obtusa Keanae taro patch Preserved_Specimen Handy, E.S. 3322 Maui BISH 1933-06-15
80 Eleocharis obtusa Upper Waiakea Forest Reserve Area 357-19. Preserved_Specimen Adee, K.T. Hawaii BISH
81 Eleocharis obtusa Ukulele Pasture above, in a damp erosion gully. Preserved_Specimen Stems rounded, dark green. Forbes, C.N. 974 Maui BISH 1919-07-29
82 Eleocharis obtusa east Kopiliula 50% open 7 m canopy; Acacia, Metrosideros, uluhe, ohia, Cheirodendron, Ilex, Clermontia arborescens, Scaevola chamissoniana, Myrsine lessertiana, Melicope, Hedyotis, Coprosma, Perrottetia, Broussaisia, Vaccinium, Styphelia, Cyrtandra, Rubus hawaiensis, ferns, bryophytes Preserved_Specimen terrestrial; covering ground; erect culms; obligate to ponding water Wood, K.R. 11338 Maui BISH 2005-05-05
83 Eleocharis obtusa Site 25 OS; Piihonua; Hilo Forest Reserve Stunted `ohi`a wetland dieback. Assoc. spp.: Metrosideros polymorpha, Acacia koa on well drained hummocks, Ilex anomala, Myrsine lessertiana, Cheirodendron trigynum, Pelea spp., Vaccinium calycinum. Soil moderately deep but poorly drained. Preserved_Specimen Adee, K.T. Hawaii BISH 1978-10-23
84 Eleocharis obtusa Malaekahana-Waimea, summit muddy Preserved_Specimen St.John, H. 17975 Oahu BISH 1937-04-04
85 Eleocharis obtusa Site 06 OS; Piihonua; Hilo Forest Reserve Stunted `ohi`a wetland dieback. Assoc. spp.: Metrosideros polymorpha (occasionally pubescent), Myrsine lessertiana, Cheirodendron trigynum, Styphelia tameiameiae, Dicranopteris sp. Soil a shallow to moderately deep, poorly drained, organic. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-06-11
86 Eleocharis obtusa Kaaawa Valley, restoration/agricultural (loi) wetland riparian area Slow flowing silted stream, open canopy. Surrounding vegetation: Ludwigia octovalvis, Paspalum scorbiculatum, Cyperus polystachyos, Fimbristylis dichotoma, Cyperus javanicus (panted), Arthrostemma ciliatum, Hyptis capitata. Preserved_Specimen Perennialized(?), bunch-forming, more spread/sprawling when mixed in competing Urochloa grass. Evans, A. 8 Oahu BISH 2024-10-17
87 Eleocharis obtusa N Kamalo bog Preserved_Specimen Hitchcock, A.S. 15106 Molokai BISH 1916-10-01
88 Eleocharis obtusa Kahana Valley clay loam Preserved_Specimen sedge Elia, H.V.K. 13 Oahu BISH 1971-02-20
89 Eleocharis obtusa Waimea Audubon Center, Waimea Valley, Oahu, Hawaii Cultivated, growing in smaller pond by Dr. Orr's office, at edges. Preserved_Specimen Tall spikes, soft, bendable, with spikelet at tip. Crago, L.M. 2005197 Oahu BISH 2005-10-18
90 Eleocharis obtusa Site 30 OS; Papaikou; Hilo Forest Reserve Stunted `ohi`a wetland dieback. Assoc. spp.: Metrosideros polymorpha, Myrsine sandwicensis, Vaccinium calycinum, Styphelia tameiameiae, Paspalum sp. Soil a thick peaty surface over poorly drained ash; substrate unkown; water at or near top. Preserved_Specimen Adee, K.T. Hawaii BISH 1979-01-12
91 Eleocharis obtusa Kealakekua, Kona (Baybrook) In swampy place Preserved_Specimen Hosaka, E.Y. 1475 Hawaii BISH 1936-08-05
92 Eleocharis obtusa Nawaimaka, Waialae falls 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; rhizome short, culms densely tufted, light brown bracts of spikelets Wood, K.R. 6973 Kauai BISH 1997-11-14
93 Eleocharis obtusa SE of Pepeopae bog small bog Preserved_Specimen Degener, O. 9001 Molokai BISH 1928-05-09
94 Eleocharis obtusa Thurston Lava Tube Culms round. Several growing on black, sandy loam in wet forest, on the trail. Preserved_Specimen Fagerlund, G.O. 697 Hawaii BISH 1943-07-03
95 Eleocharis obtusa Kaau. Ahupuaa of Waikiki, ili of Palolo. Southern Koolau mountains. Growing in swamy soil with Cladium jamaicense, Coix lacryma, Cyclosorus interruptus, Metrosideros polymorpha, Miconia crenata, Telaranea nematodea, and others. Preserved_Specimen Thomas, M.K. 815 Oahu BISH 2024-10-12
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