Hawaiian Native Plant Propagation Database
|
Brighamia rockii |
|||||
|
 |
||||
| Description The two species of Brighamia, B. insignis and B. rockii, are very similar. The main differences are the colors of the flowers and their native ranges. They are one of the most unusual plants in the Hawaiian flora. Both species have succulent stems, flower stalks that grow out from between the leaves, and tubular flowers. These plants generally have a stout, fleshy stem that is largest at the swollen, rounded base. Branched specimens are seen in the wild, but are not common in cultivation. Brighamia can reach heights of 3 to 6, occasionally 15, feet. The leaves are spoon-shaped, shiny, and leathery. They vary in color from bright to dark green. The leaves are 2 1/2 to 9 inches long and form a dense rosette at the top of the stem. Brighamia rockii blooms in the autumn. Each flower cluster of Brighamia rockii consists of 3 to 8 fragrant, white, trumpet-shaped flowers. (Hannon 2002; Koob 2000; Wagner 1999) |
|||||
| Habitat and Geographic Range Brighamia is an endemic genus and both species are endangered. Brighamia rockii grows on sea cliffs from sea level to 1,500 feet on the windward coast of Moloka'i from Kalaupapa to Halawa. It may also have previously grown on Maui and Lana'i. (Hannon 2002; Wagner 1999) |
|||||
| Propagation by Seeds Cultivated plants may begin to flower as early as their first year, but usually not for two or three years. Hand pollination should increase seed production since the native pollinator is presumed to be extinct. To hand pollinate Brighamia, use a small paint brush to transfer the pollen. When the flowers are a couple of days old, the pollen will begin being shed. Use the paint brush to pick up pollen that has fallen onto the flower tube and apply the pollen to the stigma of another flower. The stigma is ready to receive the pollen when it appears shiny and sticky. Koob states that if pollination is successful, the base of the flower will start to swell within a couple of days. The fruit of Brighamia rockii is a green capsule about 1/2 inch long which ripens six to eight weeks after pollination. When mature, the capsule splits open releasing many small, smooth seeds. Hannon states that the capsules may still be green when the open or they may have turned pale yellow or light cream in color. Some seeds may remain stuck to the sides of the capsule. The capsules can be harvested just as they start to crack open. Place the capsules in a paper bag or envelope until the seeds fall out of the open capsule. Most sources state that Brighamia seeds require light to germinate and to sprinkle the seeds on the surface of moist, fine textured medium that drains well such as fine perlite or commercial peat/perlite potting mix. Hannon suggests a light covering of fine potting medium. Use of a mist system is suggested by NTBG. Koob indicates that the seeds will begin germinating in a couple of weeks and that most seeds will sprout at the same time. Hannon reports sporadic germination beginning in two weeks. NTBG (Ragone 1993) reports that while 85% of Brighamia rockii germinated in 6 weeks, additional seeds germinated for up to 4 months with a final germination rate of 97%. Seed can be sown fresh or can be stored. Koob states that they can be kept in a refrigerator for up to 2 or 3 years. Hannon, however, writes that viability declines rapidly after 10 to 12 months. NTBG (Ragone 1993) reports that the seeds were no longer viable after storage at ambient temperature (80 degrees F) and relative humidity (25%) for 17 months. (Hannon 2002; Koob 2000; NTBG 1992; Ragone 1993; Wagner 1999) |
|||||
| Propagation by Cuttings No information located to date. |
|||||
| Propagation by Division Not applicable. |
|||||
| Propagation by Air Layers No information located to date. |
|||||
| Propagation by Grafting No information located to date. |
|||||
| Propagation by Tissue Culture Johnson reports success micropropagating Brighamia insignis. Seeds are germinated on standard agar growth media or half-strength Murashige and Skoog media. The resulting seedlings are dissected and small pieces grown on Murashige and Skoog media to which NAA (naphthaleneacetic acid) has been added. No additional details are provided. (Johnson 1986) |
|||||
| References Hannon, Dylan P. and Steve Perlman. 2002. The Genus Brighamia. Cactus and Succulent Journal 74 (2):67-76. Johnson, Margaret. 1986. Brighamia citrina var. napaliensis. Kew Magazine 3 (2):68-72. Koob, Gregory A. 2000. Cabbage on a baseball bat. Hawai'i Horticulture 3 (6):9-11. National Tropical Botanical Garden (NTBG). 1992. Alula. In Native Hawaiian plant information sheets. Lawai, Kauai: Hawaii Plant Conservation Center. National Tropical Botanical Garden. Unpublished internal papers. Ragone, Diane, (Program Coordinator). 1993. Hawaii Plant Conservation Center - Collection & Propagation Project: Progress Report (USFWS Grant 14-48-0001-92581). Lawai, Hawaii: National Tropical Botanical Garden. Wagner, Warren L., Darrel R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawai'i, rev. ed. 2 vols., Bishop Museum Special Publication 97. Honolulu: University of Hawaii Press and Bishop Museum Press. p. 422-423. |
|||||
Browse Database --
By
Botanical Name
By
Common Name
The image in this record is used with permission from Dr. Gerald Carr's Web site "Hawaiian Native Plants" at http://www.botany.hawaii.edu/faculty/carr/natives.htm
30 December 2003
Please send comments and suggestions to eherring@hawaii.edu