Delissea undulata

{{Short description|Species of plant in the family Campanulaceae}}

{{One source|date=January 2025}}

{{Speciesbox

|image =

|status = G1

|status_system = TNC

|status_ref = {{Cite web|url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.150245/Delissea_undulata|title=NatureServe Explorer 2.0|website=explorer.natureserve.org}}

|genus = Delissea

|species = undulata

|authority = Gaudich.

}}

Delissea undulata (common name {{okina}}Oha) is an extremely rare species of "palmoid" or "Corner model tree" (a pachycaulous unbranched tree superficially resembling a palm or cycad) formerly occurring on the Big Island of Hawai'i. It is cited as Extinct by the IUCN Red List and Plants of the World Online,{{cite journal | last=(DLNR-DOFAW | first=Maggie Sporck-Koehler | last2=(Lyon) | first2=Marian Chau | last3=Conservancy) | first3=Samuel Gon (The Nature | last4=Fish | first4=James Kwon (US | last5=Service) | first5=Wildlife | title=The IUCN Red List of Threatened Species | journal=IUCN Red List of Threatened Species | date=2016-01-19 | url=https://www.iucnredlist.org/species/34040/183183404 | access-date=2025-06-12 | page=}}{{cite web | title=Delissea undulata | website=Plants of the World Online | url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:142171-1 | access-date=2025-06-12}} but is also reported in cultivation from a single surviving plant found in 1992.{{cite web | title=Plants Delissea undulata subsp. undulata | url=https://dlnr.hawaii.gov/wildlife/files/2013/09/Fact-Sheet-Delissea-undulata-subsp-undulata.pdf | access-date=2025-06-12}} It is in the subfamily Lobelioideae of the family Campanulaceae. The tree is up to {{cvt|11|m}} in height but only {{cvt|5|cm}} in diameter at breast height (DBH). It never branches. The terminal rosette of wavey-edged leaves is only {{cvt|45|cm}} across. The flowers are tubular and straight. Joseph F. Rock, Indigenous Trees of the Hawaiian Islands Honolulu: published privately (1913): pages 44-45 plus photo plate 17 and p. 471