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Ceratophyllum demersum

L. (1753)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Ceratophyllopsida Order: Ceratophyllales Family: Ceratophyllaceae Genus: Ceratophyllum

coonstail, coontail, hornwort, rigid hornwort

Description

Key Characters:

Growth Form: Plants entirely submerged, aquatic, rootless perennial herbs, without secondary growth.

Stems: Stems brittle or cordlike and flexuous, 0.5–3 m long, branched, forming large masses.

Roots:

Leaves: Leaves simple (highly dissected). Leaves in whorls of 3–12 per node. Blades dichotomously dissected, variable in length, often 1–2 cm long, ultimate divisions linear. Base sessile. Surfaces glabrous. Margins serrulate. Petioles absent. Stipules absent.

Flowers: Flowers minute and inconspicuous, axillary, staminate and pistillate flowers usually solitary at different nodes, often the staminate flowers above the pistillate ones. Flowers unisexual (and the plants monoecious); Hydrogamous (pollination under water). Calyx of 8–15 linear, bract-like segments, connate at base. Corolla (petals) absent. Stamens (5–)10–20(–27), distinct, spirally arranged on the flat receptacle, not clearly differentiated into filament and anther. Ovary superior, consisting of a single carpel tapering into the style; ovule 1, pendulous, orthotropous; styles 4–6 mm long; stigma decurrent.

Fruit: Achenes ellipsoid; compressed; 4–6 mm long; wingless; with 2 basal spines 2–5 mm long. seed with thin testa; endosperm absent. Seeds with thin seed coat; endosperm absent.

Ploidy: 2n = 24; 28; 38; 48

Habitat: Naturalized in ponds and reservoirs at least on Maui and Hawai'i.

Elevation Range:

Historical Distribution

Uses and Culture

USES

Natural History

Statewide Status

Naturalized

Island Status

Kaua'i Only found in cultivation
O'ahu Naturalized
Maui Naturalized
Hawai'i Naturalized

Dispersal Agents

Water/Ocean
Birds
Other Animals

Vegetative Reproduction

Pollinators

Notes

  • Description digitized by Mercedez
  • Description digitized from the Manual of the Flowering Plants of Hawaii
  • We have seen only a few naturalized collections from Kanahd Pond, Kahului, Maui, and Hilo and Waipi'o Valley, Hawai'i. Further collections are needed to determine island distribution.

Bibliography

Name Published In: Sp. Pl.: 992 (1753)

Other References

Wagner et al. 1990:533 (M, H); Staples et al. 2002:7 (O); Oppenheimer & Bartlett 2002:5 (WM); Staples & Herbst 2005:233 (DESCR)

Occurrences

SNo. Scientific Name Scientific Name Authorship Locality Habitat Basis of Record Recorded By Record Number Island Source Date
1 Ceratophyllum demersum L. Shipman's pond, Keeau PRESERVED_SPECIMEN Kay, A. MSD 31763 Hawaii BISH
2 Ceratophyllum demersum L. Waipio Valley wetland, abandoned taro patch with Myriophyllum, Egeria, Papyrus, taro, etc. PRESERVED_SPECIMEN Stemmermann, R.L. 7141 Hawaii BISH 5/17/1987
3 Ceratophyllum demersum L. honolulu district, salt lake periphery channel PRESERVED_SPECIMEN funk, e.j. collector number: s.n. Oahu BISH 10/3/2000
4 Ceratophyllum demersum L. makawao, disturbed roadside on highway side of kanaha pond (haleakala hwy.) dominated by grasses, Pluchea indica and P. symphytifolia. Floating in canal adjacent to pond on SW corner PRESERVED_SPECIMEN wagner, w.l. imada, c.; takeuchi, w. collector number: 5803 Maui BISH 3/3/1988
5 Ceratophyllum demersum L. kahului, canal sw corner kanaha pond PRESERVED_SPECIMEN stemmermann, r.l. collector number: 7020 Oahu BISH 7/18/1985
6 Ceratophyllum demersum L. Kahului, canal SW corner Kanaha Pond floating, +/- submerged PRESERVED_SPECIMEN Stemmermann, R.L. 7020 Maui BISH 7/18/1985
7 Ceratophyllum demersum L. w maui, lahaina district, hanakaoo, kaanapali resort Submerged, forming dense mats at the south end of lagoon. PRESERVED_SPECIMEN oppenheimer, h.l. collector number: h109906 Maui BISH 10/14/1999
8 Ceratophyllum demersum L. W Maui, Lahaina District, Ukumehame Submerged in stagnant flood control channel w. Nymphaea & Eichhornia. PRESERVED_SPECIMEN Oppenheimer, H.L. Collector Number: H30137 Maui BISH 3/26/2001
9 Ceratophyllum demersum L. kailua, coconut grove area, 209 oneawa kai place PRESERVED_SPECIMEN staples, g.w. collector number: 913 Oahu BISH 2/24/1994
10 Ceratophyllum demersum L. in drainage ditch adjacent to kanaha pond PRESERVED_SPECIMEN kobayashi, s. collector number: s.n. Maui BISH 1/2/1992
11 Ceratophyllum demersum L. Makawao, disturbed roadside on highway side of Kanaha Pond (Haleakala Hwy.) dominated by grasses, Pluchea indica and P. symphytifolia. Floating in canal adjacent to pond on SW corner PRESERVED_SPECIMEN Wagner, W.L. 5803 Maui BISH 3/3/1988
12 Ceratophyllum demersum L. makawao dist., on haleakala highway side of kahana pond, floating in canal adjacent to pond on sw corner In open bog vegetation on ridgetop. PRESERVED_SPECIMEN w. l. wagner, c. imada & w. n. takeuchi 5803 Maui BISH 3/3/1988
13 Ceratophyllum demersum L. In drainage ditch adjacent to Kanaha Pond PRESERVED_SPECIMEN Kobayashi, S. s.n. Maui BISH 1/2/1992
14 Ceratophyllum demersum L. richardson's outdoor recreation center, hilo pond PRESERVED_SPECIMEN stemmermann, r.l. collector number: 7173 Hawaii BISH 7/18/1987
15 Ceratophyllum demersum L. Honolulu Submerged Aquatic PRESERVED_SPECIMEN Stemmermann, L.; 7020 Oahu HAPI 7/18/1985
16 Ceratophyllum demersum L. w maui, lahaina district, ukumehame Submerged in stagnant flood control channel w. Nymphaea & Eichhornia. PRESERVED_SPECIMEN oppenheimer, h.l. collector number: h30137 Maui BISH 3/26/2001
17 Ceratophyllum demersum L. Wailoa estuary, Hilo submerged aquatic PRESERVED_SPECIMEN Stemmermann, R.L. 7181 Hawaii BISH 7/25/1981
18 Ceratophyllum demersum L. Honolulu District, Salt Lake periphery channel PRESERVED_SPECIMEN Funk, E.J. s.n. Oahu BISH 10/3/2000
19 Ceratophyllum demersum L. W Maui, Lahaina District, Ukumehame PRESERVED_SPECIMEN J. Adams & C. Adams JWA 43 Maui HAPI 1/1/2014
20 Ceratophyllum demersum L. Honolulu District, Salt Lake periphery channel PRESERVED_SPECIMEN Funk, E.J. Collector Number: s.n. Oahu BISH 10/3/2000
21 Ceratophyllum demersum L. Honolulu, Bishop Museum glass aquarium PRESERVED_SPECIMEN Ho, A. s.n. Oahu BISH 9/6/1934
22 Ceratophyllum demersum L. Kailua, Coconut Grove area, 209 Oneawa Kai Place PRESERVED_SPECIMEN Staples, G. 913 Oahu BISH 2/24/1994
23 Ceratophyllum demersum L. Lihue District. Adams Residence Cultivated water garden, potted Undet. Hydrocharitaceae PRESERVED_SPECIMEN Adams, J. JWA_43 Kauai BISH 1/1/2014
24 Ceratophyllum demersum L. shipman's pond, keeau PRESERVED_SPECIMEN kay, a. collector number: msd 31763 Hawaii BISH
25 Ceratophyllum demersum L. Richardson's outdoor recreation center, Hilo pond PRESERVED_SPECIMEN Stemmermann, R.L. 7173 Hawaii BISH 7/18/1987
26 Ceratophyllum demersum L. waipio valley wetland, abandoned taro patch with Myriophyllum, Egeria, Papyrus, taro, etc. PRESERVED_SPECIMEN stemmermann, r.l. luce, l. collector number: 7141 Hawaii BISH 5/17/1987
27 Ceratophyllum demersum L. W Maui, Lahaina District, Ukumehame Submerged in stagnant flood control channel w. Nymphaea & Eichhornia. PRESERVED_SPECIMEN Oppenheimer, H.L. H30137 Maui BISH 3/26/2001
28 Ceratophyllum demersum L. wailoa estuary, hilo submerged aquatic PRESERVED_SPECIMEN stemmermann, r.l. luce, l. collector number: 7181 Hawaii BISH 7/25/1981
29 Ceratophyllum demersum L. W Maui, Lahaina District, Hanakaoo, Kaanapali Resort Submerged, forming dense mats at the south end of lagoon. PRESERVED_SPECIMEN Oppenheimer, H.L. H109906 Maui BISH 10/14/1999
30 Ceratophyllum demersum L. honolulu, bishop museum glass aquarium PRESERVED_SPECIMEN ho, a. Oahu BISH 9/6/1934
31 Ceratophyllum demersum L. sw corner of kanaha pond PRESERVED_SPECIMEN "stemmermann, l.;" 7020 CM 7/18/1985
32 Ceratophyllum demersum L. Kanaha Pond, Kahului Submerged Aquatic PRESERVED_SPECIMEN Stemmermann, L.; 7020 CONN 7/18/1985
33 Ceratophyllum demersum L. Lihue District, Adams Residence. PRESERVED_SPECIMEN Adams, J. W.; Adams, C. JWA 43 Kauai US 1/1/2014
34 Ceratophyllum demersum L. W. Maui. Hanakaoo. PRESERVED_SPECIMEN Hank Oppenheimer H20120 Maui PTBG 2/16/2001
35 Ceratophyllum demersum L. W. Maui, Ukumehame, near sea level. PRESERVED_SPECIMEN Hank Oppenheimer H30137 Maui PTBG 3/26/2001
36 Ceratophyllum demersum L. Adams Residence Cultivated water garden, potted PRESERVED_SPECIMEN Jesse Adams JWA_43 Kauai PTBG 1/1/2014
37 Ceratophyllum demersum L. Makawao Dist., on Haleakala highway side of Kahana Pond, floating in canal adjacent to pond on SW corner PRESERVED_SPECIMEN Wagner, W. L.; Imada, C. T.; Takeuchi, W. N. 5803 Maui US 3/3/1988
38 Ceratophyllum demersum L. lihue district, adams residence. PRESERVED_SPECIMEN j. adams & c. adams jwa 43 Kauai US 1/1/2014
39 Ceratophyllum demersum L. Lihue District, Adams Residence. PRESERVED_SPECIMEN J. Adams & C. Adams JWA 43 Kauai US 1/1/2014
40 Ceratophyllum demersum L. Shipman's pond, Keeau PRESERVED_SPECIMEN Kay, A. MSD 31763 Hawaii BISH
41 Ceratophyllum demersum L. Waipio Valley wetland, abandoned taro patch with Myriophyllum, Egeria, Papyrus, taro, etc. PRESERVED_SPECIMEN Stemmermann, R.L. 7141 Hawaii BISH 5/17/1987
42 Ceratophyllum demersum L. honolulu district, salt lake periphery channel PRESERVED_SPECIMEN funk, e.j. collector number: s.n. Oahu BISH 10/3/2000
43 Ceratophyllum demersum L. makawao, disturbed roadside on highway side of kanaha pond (haleakala hwy.) dominated by grasses, Pluchea indica and P. symphytifolia. Floating in canal adjacent to pond on SW corner PRESERVED_SPECIMEN wagner, w.l. imada, c.; takeuchi, w. collector number: 5803 Maui BISH 3/3/1988
44 Ceratophyllum demersum L. kahului, canal sw corner kanaha pond PRESERVED_SPECIMEN stemmermann, r.l. collector number: 7020 Oahu BISH 7/18/1985
45 Ceratophyllum demersum L. Kahului, canal SW corner Kanaha Pond floating, +/- submerged PRESERVED_SPECIMEN Stemmermann, R.L. 7020 Maui BISH 7/18/1985
46 Ceratophyllum demersum L. w maui, lahaina district, hanakaoo, kaanapali resort Submerged, forming dense mats at the south end of lagoon. PRESERVED_SPECIMEN oppenheimer, h.l. collector number: h109906 Maui BISH 10/14/1999
47 Ceratophyllum demersum L. W Maui, Lahaina District, Ukumehame Submerged in stagnant flood control channel w. Nymphaea & Eichhornia. PRESERVED_SPECIMEN Oppenheimer, H.L. Collector Number: H30137 Maui BISH 3/26/2001
48 Ceratophyllum demersum L. kailua, coconut grove area, 209 oneawa kai place PRESERVED_SPECIMEN staples, g.w. collector number: 913 Oahu BISH 2/24/1994
49 Ceratophyllum demersum L. in drainage ditch adjacent to kanaha pond PRESERVED_SPECIMEN kobayashi, s. collector number: s.n. Maui BISH 1/2/1992
50 Ceratophyllum demersum L. Makawao, disturbed roadside on highway side of Kanaha Pond (Haleakala Hwy.) dominated by grasses, Pluchea indica and P. symphytifolia. Floating in canal adjacent to pond on SW corner PRESERVED_SPECIMEN Wagner, W.L. 5803 Maui BISH 3/3/1988
51 Ceratophyllum demersum L. makawao dist., on haleakala highway side of kahana pond, floating in canal adjacent to pond on sw corner In open bog vegetation on ridgetop. PRESERVED_SPECIMEN w. l. wagner, c. imada & w. n. takeuchi 5803 Maui BISH 3/3/1988
52 Ceratophyllum demersum L. In drainage ditch adjacent to Kanaha Pond PRESERVED_SPECIMEN Kobayashi, S. s.n. Maui BISH 1/2/1992
53 Ceratophyllum demersum L. richardson's outdoor recreation center, hilo pond PRESERVED_SPECIMEN stemmermann, r.l. collector number: 7173 Hawaii BISH 7/18/1987
54 Ceratophyllum demersum L. Honolulu Submerged Aquatic PRESERVED_SPECIMEN Stemmermann, L.; 7020 Oahu HAPI 7/18/1985
55 Ceratophyllum demersum L. w maui, lahaina district, ukumehame Submerged in stagnant flood control channel w. Nymphaea & Eichhornia. PRESERVED_SPECIMEN oppenheimer, h.l. collector number: h30137 Maui BISH 3/26/2001
56 Ceratophyllum demersum L. Wailoa estuary, Hilo submerged aquatic PRESERVED_SPECIMEN Stemmermann, R.L. 7181 Hawaii BISH 7/25/1981
57 Ceratophyllum demersum L. Honolulu District, Salt Lake periphery channel PRESERVED_SPECIMEN Funk, E.J. s.n. Oahu BISH 10/3/2000
58 Ceratophyllum demersum L. W Maui, Lahaina District, Ukumehame PRESERVED_SPECIMEN J. Adams & C. Adams JWA 43 Maui HAPI 1/1/2014
59 Ceratophyllum demersum L. Honolulu District, Salt Lake periphery channel PRESERVED_SPECIMEN Funk, E.J. Collector Number: s.n. Oahu BISH 10/3/2000
60 Ceratophyllum demersum L. Honolulu, Bishop Museum glass aquarium PRESERVED_SPECIMEN Ho, A. s.n. Oahu BISH 9/6/1934
61 Ceratophyllum demersum L. Kailua, Coconut Grove area, 209 Oneawa Kai Place PRESERVED_SPECIMEN Staples, G. 913 Oahu BISH 2/24/1994
62 Ceratophyllum demersum L. Lihue District. Adams Residence Cultivated water garden, potted Undet. Hydrocharitaceae PRESERVED_SPECIMEN Adams, J. JWA_43 Kauai BISH 1/1/2014
63 Ceratophyllum demersum L. shipman's pond, keeau PRESERVED_SPECIMEN kay, a. collector number: msd 31763 Hawaii BISH
64 Ceratophyllum demersum L. Richardson's outdoor recreation center, Hilo pond PRESERVED_SPECIMEN Stemmermann, R.L. 7173 Hawaii BISH 7/18/1987
65 Ceratophyllum demersum L. waipio valley wetland, abandoned taro patch with Myriophyllum, Egeria, Papyrus, taro, etc. PRESERVED_SPECIMEN stemmermann, r.l. luce, l. collector number: 7141 Hawaii BISH 5/17/1987
66 Ceratophyllum demersum L. W Maui, Lahaina District, Ukumehame Submerged in stagnant flood control channel w. Nymphaea & Eichhornia. PRESERVED_SPECIMEN Oppenheimer, H.L. H30137 Maui BISH 3/26/2001
67 Ceratophyllum demersum L. wailoa estuary, hilo submerged aquatic PRESERVED_SPECIMEN stemmermann, r.l. luce, l. collector number: 7181 Hawaii BISH 7/25/1981
68 Ceratophyllum demersum L. W Maui, Lahaina District, Hanakaoo, Kaanapali Resort Submerged, forming dense mats at the south end of lagoon. PRESERVED_SPECIMEN Oppenheimer, H.L. H109906 Maui BISH 10/14/1999
69 Ceratophyllum demersum L. honolulu, bishop museum glass aquarium PRESERVED_SPECIMEN ho, a. Oahu BISH 9/6/1934
70 Ceratophyllum demersum L. sw corner of kanaha pond PRESERVED_SPECIMEN "stemmermann, l.;" 7020 CM 7/18/1985
71 Ceratophyllum demersum L. Kanaha Pond, Kahului Submerged Aquatic PRESERVED_SPECIMEN Stemmermann, L.; 7020 CONN 7/18/1985
72 Ceratophyllum demersum L. Lihue District, Adams Residence. PRESERVED_SPECIMEN Adams, J. W.; Adams, C. JWA 43 Kauai US 1/1/2014
73 Ceratophyllum demersum L. W. Maui. Hanakaoo. PRESERVED_SPECIMEN Hank Oppenheimer H20120 Maui PTBG 2/16/2001
74 Ceratophyllum demersum L. W. Maui, Ukumehame, near sea level. PRESERVED_SPECIMEN Hank Oppenheimer H30137 Maui PTBG 3/26/2001
75 Ceratophyllum demersum L. Adams Residence Cultivated water garden, potted PRESERVED_SPECIMEN Jesse Adams JWA_43 Kauai PTBG 1/1/2014
76 Ceratophyllum demersum L. Makawao Dist., on Haleakala highway side of Kahana Pond, floating in canal adjacent to pond on SW corner PRESERVED_SPECIMEN Wagner, W. L.; Imada, C. T.; Takeuchi, W. N. 5803 Maui US 3/3/1988
77 Ceratophyllum demersum L. lihue district, adams residence. PRESERVED_SPECIMEN j. adams & c. adams jwa 43 Kauai US 1/1/2014
78 Ceratophyllum demersum L. Lihue District, Adams Residence. PRESERVED_SPECIMEN J. Adams & C. Adams JWA 43 Kauai US 1/1/2014
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