Hawaiian Native Plant Propagation Database
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Dubautia spp. |
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Description There are 21 endemic species of Dubautia in the Hawaiian Islands. They range in habit from small, low shrubs to trees to woody vines. The leaf sizes and shapes are variable as is their arrangment on the stem. The flowers are yellow or white and there are generally several flowers in each head. For pictures and discussion of the many Hawaiian Dubautia species, visit Dr. Gerald Carr's Dubautia Web page. (Wagner 1990) |
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Habitat and Geographic Range The various species of endemic Hawaiian Dubautia range from common to endangered. Some species are found on all the major islands of Hawai'i and some have extremely limited ranges. Most occur at elevations above 1,500 feet with some subalpine and alpine species. Many species are found in mesic to wet forests, but some prefer dry shrublands. (Wagner 1990) |
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Propagation by Seeds Dubautia seeds are small, varying in size from 1/16 to 1/4 inch in length. Air dry the seed heads at room temperature in a bowl or paper bag. Carefully rub the fruits through a strainer with the appropriate size mesh. The seeds should fall through leaving the debris in the strainer. (Lilleeng-Rosenberger 1998) In his work, Carr soaked seeds of a variety of Dubautia species in water and germinated them on wet filter paper. Species that he grew from seed include: Dubautia arborea; D. ciliolata; D. knudsenii; D. laxa; D. linearis subsp. linearis and subsp. opposita; D. menziesii; D. microcephala; D. platyphylla; D. raillardioides; D. scabra; and, D. sherffiana. He added a small amount of fungicide (Bordeaux mix) to the papers. Carr indicated that many Dubautia species produce large numbers of infertile fruits resulting in low germination rates. His work showed that removal of the seed coat decreased germination time. He reports that fresh seeds with undamaged embryos can germinate within a few days. Lilleeng-Rosenberger's notes (1996) document germination times of about 1 month and very low germination rates ranging from 6% yo 41% for Dubautia latifolia. (Carr 1979; Lilleeng-Rosenberger 1996; Wagner 19901) |
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Propagation by Cuttings Carr rooted cuttings of a number of Dubautia species in sponge rock (perlite) under intermittent mist in a greenhouse. Rooting hormone (Rootone-F) was applied to the cuttings. The percentage of the cuttings which rooted and the time it took them to root varied quite a bit between the various species. Of the species he worked on, Dubautia scabra rooted the most quickly and Dubautia latifolia was the most difficult. Cuttings of Dubautia latifolia often took weeks to root. The other Dubautia species that Carr grew from cuttings were: Dubautia herbstobatae; D. knudsenii; D. laevigata; D. laxa; D. linearis subsp. linearis and subsp. opposita; D. menziesii; D. microcephala; D. montana (Wagner et al considers this to be a natural Dubautia hybrid); D. paleata; D. plantaginea; D. platyphylla; D. raillardioides; D. sherffiana; and, D. wainapanapaensis (now called D. dolosa). Woolliams also reported some success with rooting Dubautia knudsenii. He found that use of rooting hormones increased the number of cuttings that rooted and that treating cuttings had longer roots than untreated ones. (Carr 1979; Woolliams 1972) |
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Propagation by Division No information located to date. |
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Propagation by Air Layers No information located to date. |
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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 Carr, Gerald D. 1979. Uniform culture and propagation of Hawaiian tarweeds. Newsletter of the Hawaiian Botanical Society 18 (1/2):3-5. Lilleeng-Rosenberger, Kerin. 1996. Plant propagation notebook. Unpublished materials: National Tropical Botanical Garden. Lilleeng-Rosenberger, Kerin. 1998. Propagation techniques for native Hawaiian plants. Newsletter of the Hawaiian Botanical Society 37 (2):33-35. 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. 292-308. Wooliams, Keith. 1972. A report on the endangered species. The Bulletin of the Pacific Tropical Botanical Garden 2 (3):46-49. |
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The image in this record is used with permission from Dr. Gerald Carr's Web site "Dubautia" at http://www.botany.hawaii.edu/faculty/carr/dubautia.htm
26 August 2001
Please send comments and suggestions to eherring@hawaii.edu