Melicope oppenheimeri, section Pelea (Rutaceae), a new species from West Maui, Hawaiian Islands: with notes on its ecology, conservation, and phylogenetic placement.

Kennetah R Wood ,Marc S Appelhans,Warren L Wagner

doi:10.3897/phytokeys.69.8844

Kennetah R Wood , Marc S Appelhans + Show 1 more

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https://doi.org/10.3897/phytokeys.69.8844

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Abstract

Melicope oppenheimeri K.R. Wood, Appelhans & W.L. Wagner (section Pelea (A. Gray) Hook. f., Rutaceae), a rare endemic tree from West Maui, Hawaiian Islands, is described and illustrated with notes on its ecology, conservation, and phylogenetic placement. The new species differs from Hawaiian congeners by its carpels basally connate 1/5, narrowed into a strongly reflexed beak 10–15 mm long. It also differs in a combination of leaves with 7–10 pair of secondary veins; cymes to 3 cm long; peduncles 5–6.5 mm long; flowers perfect; capsules 4–9 × 40–52 mm; and a densely appressed short-sericeous ovary. Melicope oppenheimeri is known only from an isolated cliff-base plateau in upper Waihe‘e Valley, West Maui. Its discovery brings the number of recognized Melicope J.R. Forst. & G. Forst. species in the Hawaiian Islands to 49. A table is included indicating the conservation status of Hawaiian Melicope and Platydesma H. Mann., which is nested within Melicope sect. Pelea.Melicope oppenheimeri falls into the IUCN Critically Endangered (CR) Red List category.

Highlights

Section Pelea (Rutaceae), a new species from West Maui
Ongoing phylogenetic studies of Melicope and closely related genera indicate the need for revisionary work in this group with several of the related small genera belonging in Melicope in order for it to be monophyletic (Harbaugh et al 2009, Appelhans et al 2014b)
While Hartley’s age estimate of Melicope is doubtful since the oldest fossils of the whole family date to the Late Cretaceous (Knobloch and Mai 1986, Gregor 1989) and molecular dating studies estimated its origin in the Oligocene or Miocene (Muellner et al 2007, Appelhans et al 2012), his suggestion for a single colonization of the Hawaiian archipelago was supported by molecular phylogenetic analyses (Harbaugh et al 2009, Appelhans et al 2014b, c)

Summary

Introduction

Section Pelea (Rutaceae), a new species from West Maui Differs from Hawaiian congeners by its combination of leaves having 7–10 pair of secondary veins; cymes to 3 cm long; peduncles 5–6.5 mm long; flowers perfect; carpels basally connate 1/5, narrowed into a strongly reflexed beak 10–15 mm long, capsules 4–9 × 40–52 mm; and ovary appressed densely short-sericeous. The plant communities of upper Waihe‘e Valley are varied and merge together in and around the 0.25 km2 cliff-base plateau region where trees of Melicope oppenheimeri occur.

Results

Conclusion