Systematics Section / ASPT
Snow, Neil .
A new endemic genus of Myrtaceae from New Caledonia.
A new plant genus, tentatively named "Kanakomyrtus" (Myrtaceae) and endemic to New Caledonia , is being described (= "Gen. Nov. aff. Rhodomyrtus, e.g., Kew Bull. 55: 647-654 ). Five of the six species are to be newly described. The type of the genus and most abundant species, K. sp. "myrtopsidioides", is to be transferred from Eugenia. Based on morphological aspects of the fruit, "Kanakomyrtus" appears to be most closely related to Archirhodomyrtus, which also finds its highest species richness in New Caledonia, and some species of Rhodomyrtus, which is demonstrably polyphyletic and consists of two distinct clades. For example, the partial membranous horizontal septa in the fruits of some species of "Kanakomyrtus" suggest a close relationship to Archirhodomyrtus and some species of Rhodomyrtus (e.g., R. locellata). The hypothesized relationships among these genera also are supported by nuclear ribosomal ITS-1/ITS-2 sequence data. However, "Kanakomyrtus" differs from Archirhodomyrtus and Rhodomyrtus by its deeply and narrowly 2-4 cleft stigma, nearly straight and often pronounced secondary leaf veins, frequently dioecious sexuality, and the possession of prominent glands on the filaments, anther connectives, and (in some cases) anther sacs. The hard, bony testa places "Kanakomyrtus" in the traditionally recognized subtribe Myrtinae, although most recent studies suggest that subtribe is paraphyletic. The type specimen is the only known collection for K. sp. "quadrangulata", and most species are rare based on IUCN guidelines. The genus typically grows in mesic forests at medium to higher elevations. The generic name is a derivative of Kanak, the name native Melanesians apply to themselves in New Caledonia. This talk will characterize differences between "Kanakomyrtus" and related genera and show its tentative phylogenetic position within a large generic sampling of Myrtaceae based on ITS sequence data.
1 - University of Northern Colorado, Department of Biological Sciences, Greeley, Colorado, 80639, USA
Presentation Type: Paper
Location: Cottonwood A (Snowbird Center)
Date: Tuesday, August 3rd, 2004
Time: 3:15 PM