Hawaiian Native Plant Propagation Database
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Gossypium tomentosum |
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Description Gossypium tomentosum is a 1 1/2 to 5 foot tall shrub that can spread to 5 to 10 feet in diameter. In form it can range from a mound to a prostrate ground cover. The leaves have 3 or 5 lobes and covered with soft white hairs. The hairs give the leaves an silvery, gray-green appearance. They are usually about 4 inches wide, and not quite as long. The flowers are bright yellow, looking somewhat like a hibiscus, and are 2 to 3 inches across. Most often Gossypium tomentosum produces solitary flowers. Flowering occurs throughout the year. (Criley 1999; NTBG 1992; Wagner 1990) |
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Habitat and Geographic Range Gossypium tomentosum is an endemic shrub that is considered likely to become endangered in the near future (vulnerable status). It is threatened by coastal development and is already extinct in the wild on Kaua'i. It grows in dry, rocky, or clay coastal plains. It was found on all the main islands except Hawai'i at elevations below 390 feet. (NTBG 1992; Wagner 1990) |
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Propagation by Seeds Gossypium tomentosum seeds are enclosed in a 3 part capsule. This oval woody fruit is 1/2 to 3/4 inch long and contains 6 to 12 seeds. The small seeds are covered with reddish brown fuzz. Gossypium tomentosum grows easily from seed. Mew recommends scarification (penetrating the seed coat) to improve germination. Others recommend soaking the seeds in water for 24 hours to improve germination time. NTBG recommends cold water treatment; Bornhorst suggests hot water. Plant the seeds in a well-draining mix such as 2 parts perlite to 1 part sterile potting mix or a mix of 1 part perlite to 1 part peat moss. The pots should be placed in light shade and kept moist, but not over watered. In his germination studies, Obata found that untreated seeds of Gossypium tomentosum had extrememly variable germination rates ranging from 1 to 75%. (Bornhorst 1996; Mew 1987; NTBG 1992; Obata 1967; Rauch 1997; Wagner 1990) |
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Propagation by Cuttings Gossypium tomentosum can be grown from cuttings. Criley reports success with both softwood and semi-hardwood terminal cuttings. He recommends using a rooting hormone of 2,000 parts per million (ppm) indolebutyric acid (IBA) in either a liquid or a talc dust form. Criley suggests either 1 part coarse perlite to 1 part vermiculite or 100% vermiculite as a rooting medium. His work was done using an intermittent mist system which was on for 6 to 8 seconds every 5 or 6 minutes; cuttings were rooted under 30% shade. Cuttings root in 3 to 4 weeks. (Criley 1998; Criley 1999) |
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Propagation by Division Not applicable. |
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Propagation by Air Layers Gossypium tomentosum can be grown from air layers. (Bornhorst 1996; Rauch 1997) |
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Propagation by Grafting No information located to date. |
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Propagation by Tissue Culture No information located to date. |
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References
Bornhorst, Heidi L. 1990. Low-growing native Hawaiian plants for your garden. The Bulletin of the National Tropical Botanical Garden 20 (4):86-89. Bornhorst, Heidi L. 1996. Growing native Hawaiian plants: a how-to guide for the gardener. Honolulu: The Bess Press. p. 39. Criley, Richard A. 1998. Propagation of indigenous and endemic ornamental Hawaiian plants. Combined Proceedings of the International Plant Propagators' Society 48:669-674. Criley, Richard A. 1999. Aloha Hawai'i. American Nurseryman 190 (3):50-61. Mew, Randal K. T. 1987. Cultivation and propagation of selected coastal plants at the Waikiki Aquarium. Newsletter of the Hawaiian Botanical Society 26 (2):27-32. National Tropical Botanical Garden (NTBG). 1992. Ma'o. In Native Hawaiian plant information sheets. Lawai, Kauai: Hawaii Plant Conservation Center. National Tropical Botanical Garden. Unpublished internal papers. Obata, John K. 1967. Seed germination in native Hawaiian plants. Newsletter of the Hawaiian Botanical Society 6 (3):13-20. Rauch, Fred D., Heidi L. Bornhorst, and David L. Hensley. 1997. Ma'o (Hawaiian cotton), Ornamentals and Flowers OF-13. Honolulu: Cooperative Extension Service, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. (Also available as a PDF file at Free CTAHR Publications.) Wagner, Warren L., Darrel R. Herbst, and S. H. Sohmer. 1990. Manual of the flowering plants of Hawai'i. 2 vols., Bishop Museum Special Publication 83. Honolulu: University of Hawaii Press and Bishop Museum Press. p. 876. |
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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
5 April 2001
Please send comments and suggestions to eherring@hawaii.edu