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Acacia confusa

Merr. (1910)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Eudicot-Rosids Order: Fabales Family: Fabaceae Genus: Acacia

Formosan koa

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Description

Key Characters:

Growth Form: Trees up to 15 m tall.

Stems:

Roots:

Leaves: Leaves modified into phyllodes of petiolar origin. Alternate. Leaves reduced to phyllodes, these narrowly elliptic, slightly falcate. 6–11 cm long, 0.5–0.8 cm wide. Margins of phyllodes entire. Petiolate.

Flowers: Flowers in solitary axillary heads ca. 5 mm in diameter (excl. stamens), peduncles ca. 1 cm long. Flowers mimosaceous, ca. 2 mm long; bracteoles absent. Calyx campanulate. Corolla yellow. Stamens numerous ca. 3 mm long. Ovary superior, glabrous.

Fruit: Pods oblong in outline; flattened; 5–10 cm long; 0.7–1 cm wide; sutures partly constricted between all or most seeds; especially in younger stages. Seeds lenticular; ca. 5 mm in diameter.

Ploidy: 2n = 26

Habitat: In dry to mesic; disturbed areas.

Elevation Range: 3–915 m.

Historical Distribution

Uses and Culture

USES

Natural History

Statewide Status

Naturalized

Island Status

Kaua'i Naturalized
O'ahu Naturalized
Molokai Naturalized
Lana'i Naturalized
Kaho'olawe Naturalized
Maui Naturalized
Hawai'i Naturalized

Dispersal Agents

Forestry

Pollinators

Notes

  • Description digitized by Sam Chalekian
  • Description digitized from the Manual of the Flowering Plants of Hawaii
  • Grows from 3-915m.
  • Vernacular name: formosa koa

Bibliography

Name Published In: Philipp. J. Sci., C 5: 27 (1910)

Other References

Wagner et al. 1990:641 (K, O, Mo, L, M, Ka, H); Staples & Herbst 2005:301 (KEY, DESCR)

Occurrences

SNo. Scientific Name Locality Habitat Basis of Record Description Recorded By Record Number Island Source Date
1 Acacia confusa Reservoir betw. Waipahu and Kunia, Kunia Rd Slope: 5 degrees. Soil: silty loam. Preserved_Specimen Tree to 40' high. Narrow slightly curved leaves, yellow flowers. Afualo, D. 49 Oahu BISH 1975-03-09
2 Acacia confusa near Maunauna along gully slopes Preserved_Specimen Takeuchi, W.N. 2735 Oahu BISH 1986-08-09
3 Acacia confusa Laie Falls, Laie Hilly slopes, clay soil. Forest Areas. Preserved_Specimen Trees; Crescent-shaped leaves, thin pods; Flower is small yellow ball. Ziegelbauer, K. Oahu BISH 1975-02-18
4 Acacia confusa Nanakului Forest Reserve Located in dry, weedy area. Preserved_Specimen Small tree (about 15 ft. tall with a 6 inch dbh.) with heads of dark yellow flowers. Herbst, D.R. 673 Oahu BISH 1967-10-23
5 Acacia confusa Honolulu Distr., Wiliwilinui Trail, alongside open dirt track soon after leaving paved road portion of hike. Disturbed habitat with Casuarina equisetifolia and Acacia confusa overstory along with Psidium cattleianum and Schinus terebinthifolia. Preserved_Specimen Trees ca 18 ft height, flowers yellow, with pods. Kennedy, B. 149 Oahu BISH 2024-04-28
6 Acacia confusa W Maui, Hanaulaiki Found in scrub forest Preserved_Specimen Hobdy, R.W. 3283 Maui BISH 1991-03-05
7 Acacia confusa Waimea District. A few hundred yards north from the far north end of Polihale Beach and up the cliffs. Rocky, NW facing, moderate to steep, dry cliffs. W/Myoporum sandwicense, Lantana camara, Doryopteris decipiens. Preserved_Specimen Large shrub, about 12 feet tall. Flowers small yellow puff balls. Fruit small (3-4 inches) curved, brownish pink legumes. Walsh, S. Kauai BISH 2016-02-11
8 Acacia confusa Hawaii loa. Ridge between Niu and Wailupe. Southeastern Koolau Mountains. Growing in dry shrubland community with Metrosideros polymorpha, Casuarina equisitifolia, Sida fallax, Osteomeles anthyllydifolia, Bidens sandvicensis, Bidens alba, Sida spinosa, Desmodium, Megathyrsus maximus, Hyparrhenia rufa, and others. Preserved_Specimen Small tree rouhly 2 m. Thomas, M.K. 672 Oahu BISH 2024-05-22
9 Acacia confusa Maakua-Papali Ridge; Hauula, Koolau Range Lrg. Koa forest Preserved_Specimen Tree 10 ft. tall. Ozaki, E.T. 15 Oahu BISH 1952-10-26
10 Acacia confusa Near Aiea, Oahu Planted on dry roadside. Preserved_Specimen Degener, O. 10917 Oahu BISH 1936-11-21
11 Acacia confusa Kawaihau District: Nonou Reserve, crest of Sleeping Giant Mountain Secondary forest of guava, Java plum, and Schinus, with foresty plantings and rare native remnants. Preserved_Specimen Small tree 3 m tall, crown full, spreading. Flowers yellow, fruits green. Lorence, D.H. 5552 Kauai BISH 1987-09-13
12 Acacia confusa Round Top-Tantalus Forest Reserve. Round viewpoint Preserved_Specimen Tree to 4m; flowers yellow. Annable, C.R. 3192 Oahu BISH 1996-12-12
13 Acacia confusa University of Hawaii Campus near the Library Preserved_Specimen Fl. yellow. Shinohara, B. 217 Oahu BISH 1947-02-01
14 Acacia confusa Hilo, Hilo International Airport HUMAN_OBSERVATION Friday, J.B. Hawaii 4/22/2004
15 Acacia confusa Princeville Preserved_Specimen Small spreading tree 15 ft., 5 in. diam., planted, introduced. Little Jr., E.L. 31179 Kauai BISH 1976-09-02
16 Acacia confusa Puu Ka Pele Forest Reserve; Kaaweki Ridge Preserved_Specimen Small trees of 10 ft.; flower heads bright yellow, fragrant. Flynn, T.W. 2220 Kauai BISH 1987-06-09
17 Acacia confusa Kaluakoi, pasture land above and to west of Moomomi Beach Preserved_Specimen Small tree. Herbst, D.R. 5105 Molokai BISH 1974-11-12
18 Acacia confusa Wailua Game Reserve, above Wailua Preserved_Specimen Trees of 6 m.; flowers yellow. Howard, R.A. 20199 Kauai BISH 1985-10-20
19 Acacia confusa H.S.P.A. Plantation, Manoa District, Honolulu Preserved_Specimen Grant, M.L. 7530 Oahu BISH 1934-10-29
20 Acacia confusa 47 mi SW of Hilo on State Route 11, SW of Volcanoes National Park Preserved_Specimen Tree 5 m tall filaments yellow; fruits red-purple. Miller, J.S. 7955 Hawaii BISH 1992-08-06
21 Acacia confusa Mountains above Waimea Preserved_Specimen Flowers yellow. Krauss, N.L.H. 967 Hawaii BISH 1965-02-01
22 Acacia confusa Munro Trail, N end, 1.2 miles in from Hwy Preserved_Specimen Small tree to 3 meters; dbh 3; molassis grass assos. w/scattered trees of Psidium and Styphelia. Thalloids straight or slightly; 12 cm long by 0.8cm wide. Flower heads single in leaf axil, yellow in color. Spence, G. 333 Lanai BISH 1973-10-22
23 Acacia confusa Mountains above Waimea Preserved_Specimen Flowers yellow. Krauss, N.L.H. 967 Hawaii BISH 1965-02-01
24 Acacia confusa Kapiolani HUMAN_OBSERVATION Friday, J.B. Oahu 9/14/2003
25 Acacia confusa W Maui, Hanaulaiki Found in scrub forest Preserved_Specimen Hobdy, R.W. 3283 Maui BISH 1991-03-05
26 Acacia confusa H.S.P.A. Arboretum, Manoa Preserved_Specimen Fl. Yellow. Brown, F.B.H. 1327 Oahu BISH 1926-06-07
27 Acacia confusa Kalaupapa; Waihanau, front of dump Preserved_Specimen small tree Wysong, M.L. 602 Molokai BISH 2005-02-08
28 Acacia confusa Tantalus Drive, near Honolulu Preserved_Specimen Spreading tree, with several trunks 40 ft., 8 in. diam. Little Jr., E.L. 31001 Oahu BISH 1976-08-05
29 Acacia confusa Kapiolani HUMAN_OBSERVATION Friday, J.B. Oahu 11/18/2002
30 Acacia confusa Wiliwilinui Ridge, Koko Head Preserved_Specimen Small tree, seedlings numerous below parent trees, but not maturing; species not spreading. Tree 4 m. height. Egler, F.E. 3727 Oahu BISH 1937-11-15
31 Acacia confusa E part of island, Kapu [sp?] Ranch Preserved_Specimen Tree ca 3 m tall (but seem to vary in this area from 2 - 5 m). Lumes margins shrinking so area around each seed is scalloped and entire pod is slightly curled. Immature frt: margin is pink-purple, but most of legume is green, area where seed is located appears as a lighter green circle. Mature frt: One side is entirely purple. Silica sample deposited in the BBG Lab tissue collection.l Pell, S.K. 761 Molokai BISH 2008-07-23
32 Acacia confusa Honolulu, Kamehameha Schools, Waonahele native plantation Preserved_Specimen Munro, G.C. 5 Oahu BISH 1954-10-11
33 Acacia confusa Koloa District, land of Wahiawa, along jeep road to Alexander Reservoir Preserved_Specimen Small tree with yellow flowers. Herbst, D.R. 5565 Kauai BISH 1975-11-19
34 Acacia confusa South Hilo District, Waiakea by radio facility behind Leleiwi Point Preserved_Specimen Tree with yellow flowers. Herbst, D.R. 5305 Hawaii BISH 1975-05-19
35 Acacia confusa Waiakea Preserved_Specimen Herbst, D.R. 5305 Hawaii BISH 1975-05-19
36 Acacia confusa Manoa Valley, Arboretum of H.S.P.A Preserved_Specimen Wide spreading tree abt. 25 ft. high. Neal, M.C. Oahu BISH 1929-07-04
37 Acacia confusa University of Hawaii, Honolulu Preserved_Specimen Degener, O. 104 Oahu BISH 1923-05-24
38 Acacia confusa Kamehameha Girls' School, Honolulu Preserved_Specimen Grant, M.L. 7131 Oahu BISH 1934-07-31
39 Acacia confusa Waiakea Preserved_Specimen Herbst, D.R. 5305 Hawaii BISH 1975-05-19
40 Acacia confusa Honolulu, Diamond Head Preserved_Specimen Munro, G.C. 56 Oahu BISH 1958-01-01
41 Acacia confusa Wiliwilinui Ridge Preserved_Specimen Egler, F.E. 3727 Oahu BISH 1937-06-15
42 Acacia confusa Fenced forestry planting just SW of Lua Makika Preserved_Specimen Formosa Koa, small Phillipine acacia. Clarke, G. 214 Kahoolawe BISH 1980-04-25
43 Acacia confusa West Maui, Hanaulaiki, near the bottom of the powerline road. Preserved_Specimen Hobdy, R.W. 3224 Maui BISH 1990-07-24
44 Acacia confusa East Maui, Haleakala National Park along the Palikea stream below the bridges. Preserved_Specimen Welton, P. 2442 Maui BISH 2019-05-20
45 Acacia confusa East Maui, along Hana Hwy., 23 mi from Hana Post Office (on Wailuku side), Haipuaena Gulch Preserved_Specimen Ishikawa, S. 346 Maui BISH 1973-12-01
46 Acacia confusa United States. Hawaii, Aiea Loop Trail, Koolau Mts. Preserved_Specimen Ziegler, M.F. Oahu BISH 1987-06-10
47 Acacia confusa Kula, Ao Malie Farm Preserved_Specimen Richards, L.P. Maui BISH 1978-08-29
48 Acacia confusa Wiliwilinui Ridge, Waialae Iki Preserved_Specimen Kondo, Y. Oahu BISH 1951-07-14
49 Acacia confusa Honolulu, University of Hawaii Campus Preserved_Specimen Bryan Jr., E.H. Oahu BISH 1936-07-11
50 Acacia confusa Mid-Pac Preserved_Specimen Adee, K.T. Oahu BISH
51 Acacia confusa Kapalama Hts., Kamehameha Girls' School Preserved_Specimen Judd Jr., A.F. Oahu BISH 1932-06-06
52 Acacia confusa Koolau Range, Kipapa Gulch Trail Preserved_Specimen Cowan, R.S. 90 Oahu BISH 1946-09-29
53 Acacia confusa Haukulu, upper Manoa Valley Preserved_Specimen Harris, J.A. 242258 Oahu BISH 1924-09-26
54 Acacia confusa Laie Slope 1; Soil Clay. Preserved_Specimen Pasture; Tree with alternate leaves. Guinto, J. 26 Oahu BISH 1986-03-09
55 Acacia confusa West Maui, Hanaulaiki, near the bottom of the powerline road. Scattered through low pukiawe, aalii, and ohia scrub. Preserved_Specimen Small trees or shrubs, 4-12 ft tall, curiously erect! No pods seen. Hobdy, R.W. 3223 Maui BISH 1990-07-24
56 Acacia confusa Kapano Gulch Planted on sunny flats. Preserved_Specimen Degener, O. 28449 Lanai BISH 1963-07-28
57 Acacia confusa Koloa District. N facing slope of Polihale Ridge in Hikimoe valley, growing on rocky dry hillside. Dry weedy shrubland W/Lantana camara, Myoporum sandwicense, Doryopteris decipiens. Preserved_Specimen Tree 2.5m tall with diminuitive bright yellow flowers, leaves dark green above, silvery below. Deans, S.M. 31 Kauai BISH 2016-02-11
58 Acacia confusa UH Manoa, Korean Studies Center full sun Preserved_Specimen 6 m tree; flowers buttercup yellow, slightly fragrant (morning) Lau, J. 1113 Oahu BISH 1985-06-18
59 Acacia confusa Honolulu, Lanipo Trail Common along trail. Preserved_Specimen Tree, 7-8 ft ht, corolla yellow. Kennedy, B. 8 Oahu BISH 1995-11-21
60 Acacia confusa Sunset Beach Slope 0; Soil sandy. Preserved_Specimen Tree; Densely compact tree 5-8 m. high. Lee, W. Oahu BISH 1967-03-06
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