Tropical Plant Database - Plant Details

Endemic to Kaua'i island, Trematolobelia kauaiensis (Koli'i in Hawaiian) is a lobeliaceous plant, with horizontally spreading floral spikes and purplish red flowers, sitting atop a pole-like stem that never branches. Plants are 0.9 to 4 m (~ 3-13 ft) tall, with stems 0.7 to 1.6 centimeters (~ 0.28-0.63 in) in diameter. The leaves of Trematolobelia kauaiensis are dark green on the upper surface, with the lower surface pale green, linear-elliptic to elliptic in shape. Inflorescences composed of 5-10 horizontal branches 20-58 cm long, each 20-32 flowered. The fruit look as though they ought to become berries, but the fleshy parts fall away to reveal a porous woody capsule which disperses seeds. The seed capsules are subglobose in shape.

• Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawaii. University of Hawaii Press, Bishop Museum Press, Honolulu, Hawaii.


• Wagner, W.L., Herbst, D.R., & Lorence, D.H. (2005-). Flora of the Hawaiian Islands website. http://botany.si.edu/pacificislandbiodiversity/hawaiianflora/index.htm


• Lammers, T. G. 2009. Revision of the Endemic Hawaiian Genus Trematolobelia (Campanulaceae: Lobelioideae). Brittonia, vol. 61, no. 2, pp. 126–143. JSTOR, www.jstor.org/stable/40648097

This database entry has been complied by Matthew Kahokuloa, Jr.

Conservation strategies include continuing surveys of population and distribution of Trematolobelia kauaiensis in known and likely habitats, establishing secure ex-situ stocks with complete representation of remaining individuals, increasing wild populations and establish new populations in safe areas, and monitoring Trematolobelia kauaiensis for insect damage and plant diseases.

Trematolobelia kauaiensis is endemic to Kaua‘i, growing at 990-1570m in elevation on the central plateau, particularly in and around the Alaka‘i Swamp; and at 730-1200m in the Wahi'awa drainage of the southern portion of the island. These areas are dominated by various Lowland Wet Shrubland, Montane Wet Shrubland, and Lowland Wet Forest communities. Flowering commences in August and continues through early November.

• Lammers, T. G. 2009. Revision of the Endemic Hawaiian Genus Trematolobelia (Campanulaceae: Lobelioideae).” Brittonia, vol. 61, no. 2, pp. 126–143. JSTOR, www.jstor.org/stable/40648097.

The curved flowers of Trematolobelia kauaiensis suggest them to be ornithophilous, indicating possible coevolution with curved-beaked native forest birds — mostly honeycreepers (Drepanididae). The porous woody seed capsule strongly suggest that seeds were wind-dispersed. Undoubtedly the shaking afforded by winds, as actually observed in the field, does promote escape of seeds through the pores. The winged nature of seeds undoubtedly is probably effective in permitting more widespread distribution (presumably by wind) of seeds.

• Lammers, T. G., Freeman, E. C. 1986. Ornithophily among the Hawaiian Lobelioideae (Campanulaceae): Evidence from Floral Nectar Sugar Compositions. https://bsapubs.onlinelibrary.wiley.com/doi/abs/10.1002/j.1537-2197.1986.tb10913.x


• Carlquist, S. 1962. Trematolobelia: Seed Dispersal; Anatomy of Fruit and Seeds. Pacific Science Vol. 16, pp 126-134. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2664350/


• Givnish TJ, Millam KC, Mast AR, et al. 2009. Origin, adaptive radiation and diversification of the Hawaiian lobeliads (Asterales: Campanulaceae). Proc Biol Sci. 276(1656):407-416. https://doi.org/10.1098/rspb.2008.1204

Name derived from the Greek trematos, hole (in reference to the perforated capsule), and the genus Lobelia, to which the type species, Trematolobelia macrostachys, was originally assigned.

• Wagner, W. L., Herbst, D. R., and S. H. Sohmer. 1999. Manual of the Flowering Plants of Hawaii. University of Hawaii Press, Bishop Museum Press, Honolulu, Hawaii.

IUCN Status: Endangered (E): Trematolobelia kauaiensis is assessed as Endangered (B1ab(iii)+2ab(iii)). The taxon is endemic to the island of Kaua'i and has an extent of occurrence of 357.6 km2. It has experienced ongoing decline in habitat quality due to the impacts of invasive plants and animals. Its area of occupancy is 170 km2. Its distribution is severely limited, occurring in only five subpopulations.

Federal Listing Status: No Status: Trematolobelia kauaiensis has not been proposed for listing under the United States Endangered Species Act, and is not listed under Hawai'i State Law.

The major threats to this taxon include direct competition by invasive non-native plant species. The taxon is predated and habitat degraded by non-native animals, including rats and pigs.

• Wolkis, D. 2018. Trematolobelia kauaiensis. The IUCN Red List of Threatened Species 2018: e.T97911574A97911585. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T97911574A97911585.en

We currently have 44 herbarium specimens for Trematolobelia kauaiensis in our collection. Click on any specimen below to view the herbarium sheet data.

• 029603 - collected by George Gillett in 1964
• 004536 - collected by John J. Fay in 1973
• 004533 - collected by John J. Fay in 1974
• 004535 - collected by Thomas B. Croat in 1978
• 004534 - collected by Tim Flynn in 1982
• 004538 - collected by David H. Lorence in 1987
• 004532 - collected by David H. Lorence in 1988
• 014016 - collected by K. R. Wood in 1988
• 004537 - collected by Tim Flynn in 1988
• 010766 - collected by Tim Flynn in 1991
• 041210 - collected by K. R. Wood in 1991
• 041211 - collected by K. R. Wood in 1991
• 019377 - collected by Steve Perlman in 1994
• 029716 - collected by K. R. Wood in 1996
• 021500 - collected by Steve Perlman in 1996
• 021583 - collected by Steve Perlman in 1996
• 055079 - collected by K. R. Wood in 1998
• 045685 - collected by Steve Perlman in 2003
• 061953 - collected by K. R. Wood in 2007
• 061935 - collected by K. R. Wood in 2007
• 072847 - collected by Natalia Tangalin in 2012
• 067154 - collected by Natalia Tangalin in 2012
• 069265 - collected by Steve Perlman in 2014
• 082715 - collected by K. R. Wood in 2014
• 080224 - collected by K. R. Wood in 2018
• 080258 - collected by K. R. Wood in 2018
• 081666 - collected by K. R. Wood in 2019
• 081665 - collected by K. R. Wood in 2019
• 079913 - collected by K. R. Wood in 2019
• S079684 - collected by K. R. Wood in 2019
• 082345 - collected by K. R. Wood in 2020
• Unassigned - collected by Dustin Wolkis in 2021
• 085645 - collected by Dustin Wolkis in 2021
• Unassigned - collected by Dustin Wolkis in 2021
• Unassigned - collected by Dustin Wolkis in 2021
• 085813 - collected by Dustin Wolkis in 2021
• Unassigned - collected by Dustin Wolkis in 2021
• 085444 - collected by Dustin Wolkis in 2021
• Unassigned - collected by Dustin Wolkis in 2021
• Unassigned - collected by Dustin Wolkis in 2021
• 085840 - collected by Dustin Wolkis in 2021
• 092654 - collected by Dustin Wolkis in 2022
• 092900 - collected by Dustin Wolkis in 2022
• Unassigned - collected by K. R. Wood in 2023