Delissea rhytidosperma (cultivated)

• Conservation Status: Endangered
• Distribution: Kaua’i
• Date photographed: 1/3/2012
• Ease of viewing: Cultivated
• *Identification: Form– Shrub, 0.5-2.5 m tall. Leaves– 8-19 cm long, 2.0-5.5 cm wide; oblanceolate, elliptic, or narrowly elliptic; margins serrulate or crenulate Flower– calyx lobes 0.5-1.0 mm long, 0.5-0.7 mm wide, glabrous; 14-24 mm long
• Phylogenetic comments: Delissea was provincially split into two groups: plants with small greenish-white flowers were placed in the sect. delissea. D. rhytidosperma was part of this group but recent work (Lammers, 2005) has placed it into a newly erected sect. rhytidospermae. Several species were known, but D. rhytidosperma is the only one to be currently extant. 2022 update — New genetic work seems to show that D. rhytidosperma and D. kauaiensis form a clade sister to the remaining Delissea spp.
• My notes: This highly endangered plant is known from a few wild plants in mesic forest on Kaua’i. Luckily, it does well in cultivation. Delissea rhytidosperma is one of the most commonly available lobeliads to the average gardener here in Hawai’i.
• Links: Delissea rhytidosperma SGCN (pdf), 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 Manual of the Flowering Plants of Hawai’i