Lepidium didymum

L. (1767)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Eudicot-Rosids Order: Brassicales Family: Brassicaceae Genus: Lepidium

ihiihiione (Niihau via St. John), peppergrass, pepperwort, swinecress, swinecress

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Description

Key Characters:

Growth Form: Sparsely pubescent, aromatic annual or biennial herbs.

Stems: Outer stems prostrate, 1–4 dm long.

Roots:

Leaves: Leaves simple. Alternate or rarely opposite. Basal leaves oblong in outline, 3–10 cm long, deeply pinnatifid. stem leaves similar but shorter. Margins lobed, lobes dentate. Petioles of basal leaves 0.5–4(–6) cm. Cauline leaves petiolate to subsessile. Stipules absent.

Flowers: Flowers in racemes usually axillary. Flowers bisexual (perfect), actinomorphic or rarely slightly irregular. Calyx of 4 sepals, deciduous, erect, usually oblong, sometimes the inner 2 with gibbous bases that hold the nectar. Corolla of 4 petals, white, spatulate, scarcely exceeding the sepals, ca. 1 mm long. Stamens 2 tetradynamous, the inner 4 usually in pairs, sometimes connate at base in pairs; anthers dithecal, opening by longitudinal slits. Ovary superior, 2(4?)-carpellate, usually 2-celled by means of a false, but usually complete septum, rarely 1-celled, sessile or rarely stipitate; ovules 1 to numerous, borne on parietal placentas on replum margin at periphery of ovary wall, campylotropous or occasionally anatropous; style 1 or occasionally absent; stigma capitate.

Fruit: Capsules divided into 2 cells by the usually thin and membranous septum; elongate (at least 3 times as long as wide) referred to as a silicle; deeply constricted at apex and base; producing a fruit with 2 globose halves on opposite sides of a narrow partition; indehiscent; reticulate or wrinkled; sometimes tuberculate; didymous; 2–2.5 mm wide; finely wrinkled. Seeds 1 per cell; often becoming mucilaginous when wet; endosperm essentially absent.

Ploidy: 2n = 32

Habitat: Naturalized in dry; disturbed sites; especially common in lawns.

Elevation Range: 0–2100 m.

Historical Distribution

Images

Uses and Culture

USES

Natural History

Statewide Status

Naturalized

Island Status

Mokupāpapa (Kure atoll) Naturalized
Ni'ihau(Incl. Lehua) Naturalized
Kuaihelani (Midway Atoll) Naturalized
Kaua'i Naturalized
Manawai (Pearl & Hermes Atoll) Naturalized
O'ahu Naturalized
Molokai Naturalized
Kamole(Laysan Island) Extirpated
Lana'i Naturalized
Kaho'olawe Naturalized
Maui Naturalized
Hawai'i Naturalized

Dispersal Agents


Pollinators

Bibliography

Name Published In: Mant. Pl.: 92 (1767)

Other References

Wagner et al. 1990:403 (Mi, PH, Ni, K, O, Mo, L, M, Ka, H [as Coronopus didymus]); Al-Shehbaz et al. 2002:6 (Syn. C. didymus = L. didymum); Staples et al. 2003:9 (La); Imada & Kennedy 2020:72 (Ku); Starr & Starr 2013b (La†, 2013)

Occurrences

SNo. Scientific Name Locality Habitat Basis of Record Recorded By Record Number Island Source Date
1 Lepidium didymum East Maui, Haleakala Crater, Paliku Control Cabin Growing with kikuyu grass in cleared area around cabin. Preserved_Specimen Nagata, R. Maui BISH 1986-07-14
2 Lepidium didymum Upper Makakilo, adjacent to developed subdivision at end of Pueonani Street Open area in solid Panicum maximum grassland, with /Waltheria indica, Sida fallax, Eleusine indica, Verbesina encelioides, Sonchus oleraceus. Preserved_Specimen Imada, C. 200424 Oahu BISH 2004-03-09
3 Lepidium didymum HNP, Maui Halemau Trail Grows in a tangles mass with very disagreeable odor. Preserved_Specimen Olson, G.E. 62 Maui BISH 1937-07-11
4 Lepidium didymum Koloa District, Prince Kuhip Park in Poipu, Makai of Nahumaalo Point and Lawai Road. East of Prince Kuhio Resort edge of rock-lined pond. Manicured grassy area of park with lava rock-lined pond. W/ Medicago lupulina, Medicago polymorpha, Ficus microcarpa, Parthenium hysterophous, Indigofera spicata, Thespesia populnea, Lepidium virginicum, Coronopus didymum, Chloris virgata, Mimosa pudica, Pl Preserved_Specimen Tangalin, N. 5174 Kauai BISH 2021-04-23
5 Lepidium didymum Kalaupapa; peninsula, base of lighthouse stairs along rock wall Preserved_Specimen Wysong, M.L. 617 Molokai BISH 2005-02-08
6 Lepidium didymum Ulupau Head, Mokapu Peninsula (?) Sandy bottom of gully Preserved_Specimen Fosberg, F.R. 10905 Oahu BISH 1935-05-26
7 Lepidium didymum E central part of island, between Kaulana Gulch and base of Moaula Growing on eroded slope in Andropogon pertusus grassland. Preserved_Specimen Cuddihy, L.W. 423 Kahoolawe BISH 1980-04-25
8 Lepidium didymum Molokini Islet rare along inner slope. Preserved_Specimen Hobdy, R.W. 1228 Maui BISH 1982-02-14
9 Lepidium didymum Airplane field, in ,owed grass, Kapaa Quarry Road, Kailua In mowed grass at edge of airplane field. Soil moist, loamy. Full sun. Preserved_Specimen Crago, L.M. 2005021 Oahu BISH 2005-01-20
10 Lepidium didymum James Campbell National Wildlife Refuge, Kahuku. In vicinity of bird-viewing gazebo Weed on dry ground on levee between ponds. Collection made under sponsorship by Ducks Unlimited, Inc. Preserved_Specimen Imada, C. 9217 Oahu BISH 1992-04-05
11 Lepidium didymum Kokee State Park. Mohihi Rd. near Waineke Swamp Common along road. Preserved_Specimen Flynn, T.W. 974 Kauai BISH 1984-08-28
12 Lepidium didymum South Kohala District, east of Queen Kaahumanu Hwy, between Mauna Lani Drive and Puako turnoff. Dry area with scant vegetation; open grassland with scattered Prosopis pallida. Preserved_Specimen Funk, E.J. 27 Hawaii BISH 1991-02-04
13 Lepidium didymum West end of Mahaulepu area Locally common in pockets of soil at top of limestone cliffs overlooking the ocean. Preserved_Specimen Fay, J.J. 167 Kauai BISH 1974-02-01
14 Lepidium didymum U.H. Campus, Mauka Field Laboratory (Dept. of Agronomy and Soils) A weed growing on a dirt pile in full sun. Preserved_Specimen Lau, J. 2250 Oahu BISH 1986-04-15
15 Lepidium didymum Green Island around LORAN Bldgs and roadsides in that area. Preserved_Specimen Herbst, D.R. 6252 Kure Atoll BISH 1979-01-04
16 Lepidium didymum West Molokai, Kaeo Cliffs Common locally at tops of cliffs of volcanic rock Preserved_Specimen Fosberg, F.R. 29583 Molokai BISH 1948-02-22
17 Lepidium didymum Keauhou Ranch Growing along Pu'u O'o Road near a paddock. Preserved_Specimen Davis, J. 725 Hawaii BISH 1982-05-05
18 Lepidium didymum Pacific Remote Islands National Wildlife Refuge, in flat rocky area, ca 200 m from beach Collected at former guano mining site, in area with high concentration of albatross nestings. Most species in area are alien: Sporobolus, Solanum americanum, Conyza bonariensis. Preserved_Specimen Martin, A. 2 Laysan Island BISH 2002-03-12
19 Lepidium didymum Popoia Islet, Oahu on west side near coast growing in sands inside limestone hole. Preserved_Specimen Starr, F. 502237 Oahu BISH 2005-02-23
20 Lepidium didymum East Molokai, North Coast, Kukaiwaa on windswept peninsula Growing in a thick carpet of Fimbristylis pycnocephala, low prostrate. Preserved_Specimen Hobdy, R.W. 2185 Molokai BISH 1984-08-27
21 Lepidium didymum Kalaupapa National Historical Park Coastal strand vegetation. Plant invading post-deer damage. Preserved_Specimen Gagné, B.H. 3153 Molokai BISH 2000-09-17
22 Lepidium didymum Between J.C.Campbell Refuge and Beach Tropical Coastal Plants Preserved_Specimen Smith, M. 22 Oahu BISH 1986-04-08
23 Lepidium didymum Area between Puu Moaula and Lua Makika growing in grassland area Grassland Preserved_Specimen Higashino, P.K. 8039 Kahoolawe BISH 1978-11-22
24 Lepidium didymum Koko Crater, dry open slopes Preserved_Specimen Christophersen, E. 1301 Oahu BISH 1930-04-06
25 Lepidium didymum Honolulu Preserved_Specimen Forbes, C.N. 1026 Oahu BISH 1909-01-15
26 Lepidium didymum Uwekahuna Blutt. Found in shade Preserved_Specimen Fagerlund, G.O. 452 Hawaii BISH 1943-03-15
27 Lepidium didymum Ewa Plains Survey-U.S.F.&W. Campbell Industrial Park area Preserved_Specimen Higashino, P.K. 8193 Oahu BISH 1979-02-01
28 Lepidium didymum Ewa Beach Preserved_Specimen Char, W.P. 144 Oahu BISH 1982-01-30
29 Lepidium didymum Palawai, Kaluanui Flats Preserved_Specimen Herbst, D.R. 5802 Lanai BISH 1976-04-01
30 Lepidium didymum Southeast Island. Collected from an extensive, nearly pure colony growing on the northern side of the western part of the islan Preserved_Specimen Herbst, D.R. 6489 Hawaii BISH 1980-07-07
31 Lepidium didymum Along the highway near the lands of Waialua Preserved_Specimen Herbst, D.R. 5750 Molokai BISH 1976-03-10
32 Lepidium didymum P.T.B.G., Lawai Valley Uncommon in Valley. Native to Eurasia. Preserved_Specimen Herbst, D.R. 2274 Kauai BISH 1971-12-30
33 Lepidium didymum Mouth of Halawa Valley, grassy sand flat, much trampled, Preserved_Specimen Fosberg, F.R. 13408 Molokai BISH 1936-12-25
34 Lepidium didymum E central part of island, slope of Moaula Preserved_Specimen Cuddihy, L.W. 433 Kahoolawe BISH 1980-04-25
35 Lepidium didymum Coral plain below Ewa Mill & Sisal Preserved_Specimen Forbes, C.N. 2325 Oahu BISH 1916-05-14
36 Lepidium didymum Kaeo Cliffs, West Molokai Preserved_Specimen Fosberg, F.R. 29583 Molokai BISH 1948-02-22
37 Lepidium didymum Hawaii Preserved_Specimen Mann, H. 331 Hawaii BISH 1864-01-01
38 Lepidium didymum Miki Preserved_Specimen Munro, G.C. 254 Lanai BISH 1913-12-21
39 Lepidium didymum Parker ranch, Pokanaka, plowed field Preserved_Specimen Ewart III, G.R. 174 Hawaii BISH 1932-04-21
40 Lepidium didymum Parker Ranch, Nienie Hawaii Preserved_Specimen Rock, J.F.C. 8325 Hawaii BISH 1910-06-01
41 Lepidium didymum Lanai Preserved_Specimen Munro, G.C. 286 Lanai BISH 1913-12-06
42 Lepidium didymum Auwahi, S slope of Haleakala Preserved_Specimen Forbes, C.N. 2023 Maui BISH 1920-03-19
43 Lepidium didymum University of Hawaii campus Preserved_Specimen St.John, H. 10461 Oahu BISH 1930-04-05
44 Lepidium didymum Koloa District. Mahaulepu. In Casuarina grove in dumes behind Haula Preserved_Specimen Flynn, T.W. 1969 Kauai BISH 1986-11-25
45 Lepidium didymum Coral plain below Ewa and Sisal Preserved_Specimen Forbes, C.N. 2325 Oahu BISH 1916-03-14
46 Lepidium didymum Crest of Koolau Range, head of Kamiloiki valley Preserved_Specimen Egler, F.E. 37110 Oahu BISH 1937-06-12
47 Lepidium didymum Lanai City Preserved_Specimen Degener, O. 28557 Lanai BISH 1963-08-15
48 Lepidium didymum Mokuleia Beach, Waialua Preserved_Specimen Degener, O. 24342 Oahu BISH 1957-01-01
49 Lepidium didymum Honolulu, grounds of Bishop Museum Preserved_Specimen Neal, M.C. Oahu BISH 1952-05-06
50 Lepidium didymum Koko Head, Maunalua Preserved_Specimen Krauss, N.H. Oahu BISH 1933-03-25
51 Lepidium didymum Honolulu, Bishop Museum Grounds Preserved_Specimen Suehiro, A. Oahu BISH 1963-02-13
52 Lepidium didymum Tantalus in Honolulu Preserved_Specimen Forbes, C.N. Oahu BISH 1909-03-31
53 Lepidium didymum Laniloa (?) Preserved_Specimen Cooke, C.M. Oahu BISH 1919-02-01
54 Lepidium didymum Koko Head Preserved_Specimen Swezey, O.H. Oahu BISH 1920-01-01
55 Lepidium didymum Moanalua Valley Preserved_Specimen Forbes, C.N. Oahu BISH 1909-02-18
56 Lepidium didymum Makaha Valley Preserved_Specimen Suehiro, A. Oahu BISH 1932-04-03
57 Lepidium didymum Oahu Preserved_Specimen Forbes, C.N. Oahu BISH 1909-03-31
58 Lepidium didymum yard of home H.B. Castle Homestead, Honolulu Preserved_Specimen Student at University of Hawaii Oahu BISH 1931-02-26
59 Lepidium didymum Honopu Beach Preserved_Specimen Joyce Kauai BISH 1984-07-18
60 Lepidium didymum Tantalus, Honolulu Preserved_Specimen Forbes, C.N. Oahu BISH 1908-03-31
61 Lepidium didymum Southeast Island, part of the Northwest Hawaiian Islands National Wildlife Refuge Preserved_Specimen Wegmann, A. Pearl & Hermes Atoll BISH 2001-10-03
62 Lepidium didymum Oahu Sugar Co Preserved_Specimen Swezey, O.H. Oahu BISH 1930-05-20
63 Lepidium didymum Along road leading to Kaluanui Valley Preserved_Specimen Corn, C. Oahu BISH 1978-03-21
64 Lepidium didymum Kilauea Crater Preserved_Specimen Meebold, A. Hawaii BISH 1932-05-01
65 Lepidium didymum Taauhau 2 Preserved_Specimen Rock, J.F.C. Hawaii BISH 1910-06-01
66 Lepidium didymum Niihau Preserved_Specimen Stokes, J.F.G. Niihau BISH 1912-01-01
67 Lepidium didymum Molokai Pukoo Preserved_Specimen Faurie, A. Molokai BISH 1910-06-01
68 Lepidium didymum Honolulu, Library of Hawaii, lawn weed Preserved_Specimen Smith, D. Oahu BISH 1952-03-13
69 Lepidium didymum Kamehameha school campus Preserved_Specimen Brown, F.B.H. 1321 Oahu BISH 1924-12-31
70 Lepidium didymum Kaimuki, Honolulu, Hawaii Preserved_Specimen Topping, D.L. 2995 Oahu BISH 1925-01-21
71 Lepidium didymum Alekoko Valley (?) Preserved_Specimen Kauai BISH 1926-06-14
72 Lepidium didymum Lanai Preserved_Specimen Forbes, C.N. Lanai BISH
73 Lepidium didymum Mokuauia Islet, Oahu in central western part of island Preserved_Specimen Starr, F. 502223 Oahu BISH 2007-02-22
74 Lepidium didymum In pineapple field Preserved_Specimen Hosaka, E.Y. 470 Lanai BISH 1931-06-23
75 Lepidium didymum Hawaii Preserved_Specimen Rock, J.F.C. 2666 Hawaii BISH