Delissea kauaiensis (cultivated)

• Conservation Status: Endangered
• Distribution: Kaua’i
• Date photographed: 6/26/2013
• Ease of viewing: Cultivated
• *Identification: Form– Treelet or tree (rarely sparingly branched), 1.2-4.5 m tall. Leaves– 5.7-19.0 cm long, 2-11 cm wide, ovate or lanceolate, margin coarsely biserrate or crenate. Flower– Calyx lobes 0.5-2.0 mm long, 0.3-0.7 mm wide; Corolla 16-30 mm long
• Phylogenetic comments: The Delissea undulata complex was split up into 4 different species (Lammers, 2005). Only the species from Kaua’i and Big Island are currently known to be extant. These 4 species form the now reduced sect. Delissea. 2022 update — Previously thought to be closely related to the Big Island D. argutidentata, current genetic works shows that D. kauaiensis nests with its island sympatric relative D. rhytiosperma.
• My notes: Until I read the recent Delissea monograph, I was unsure of the differences between the 2 Kaua’i species. Delissea kauaiensis differs from D. rhytidosperma by a number of morphological features. D. kauaiensis has leaves in short internodes; the leaves form a dense apical rosette. In D. rhytidosperma the leaves are more widely spaced on the stem. D. kauaiensis rarely branches unlike D. rhytidosperma. Also, the flowers on D. kauaiensis typically have 3 knobs on the corolla, D. rhytidosperma only has one.
• Links:  Smithsonian Flora of the Hawaiian Islands, UH Botany, Native Hawaiian Plants- Delissea
• Refs: Lammers, T. G. (2005). Revision of Delissea (Campanulaceae-Lobelioideae).Systematic Botany Monographs, 1-75.

*From Lammers Revision of Delissea