A New Species of Hawaiian Phyllostegia (Lamiaceae) from Kaua'i and Recognition of a Wai'anae Mountain, O'ahu, Endangered Variety of Phyllostegia parviflora

Abstract

A rare new species of the Pacific genus Phyllostegia, P renovans, is described. It is unique in the genus in that the stems resume vegetative growth after flowering. It is relatively rare, with 23 small populations known only from three adjacent valleys on the northeastern part of the island of Kaua'i, Hawaiian Islands. A new combination is also provided for the Wai'anae Mountains, O'ahu, endangered endemic variety of Phyllostegia parvflora now known from only one extant population of about 20 individuals. The intensive collecting effort by the National Tropical Botanical Garden collectors during the past decade has shown that Kaua'i was one of the least effectively collected Hawaiian Islands. Kaua'i is among the most interesting because it has the highest level of single-island endemism in the archipelago (Wagner et al., 1990; Sakai et al., 1995; Wagner & Funk, 1995). Especially in need of intensive survey effort was the northeastern quadrant of Kaua'i. A number of new species and many range extensions have been made in the past several years of work in this region of the island. One of these new species is a Phyllostegia with a unique growth habit, in which the vegetative stem reinitiates growth after flowering. Two additional basic inflorescence patterns occur in the genus: short, congested inflorescences on usually leafless lateral branches in the axils of or below the lowermost leaves (e.g., Pr floribunda Bentham, P wawrana Sherff); and leafy, terminal, racemose inflorescences on the central stem and upper lateral branches (most of the genus, including P parvflora (Gaudichaud) Bentham). The renewal of vegetative growth can be viewed as an intermediate stage between the usual type in Phyllostegia and the short, congested, lateral type in two species of Phyllostegia. The lateral type in turn has evolved further into the axillary verticillasters in Stenogyne, a closely related Hawaiian genus of primarily bird-pollinated vines. Phyllostegia renovans W. L. Wagner, sp. nov. TYPE: Hawaiian Islands (U.S.A). Kaua'i: Hanalei District, headwaters of Wainiha River, NE fork, just SW of Mahinakehau Ridge, lowland wet forest with Metrosideros polymorpha Gaudichaud dominant, slopes moderate to steep, occasional in clearings, wet soil, 680-825 m, 29-30 Jan. 1993, D. H. Lorence, S. Perlman & K. Wood 7315 (holotype, US-3362751; isotypes, BISH, PTBG). Figure 1. Caulibus brevihirsutis, post anthesin recrescentibus; floribus (4)6 in quoque verticillastro; calyce 8-12 mm longi, marginibus loborum uni-paucidentatis, corolla alba, 19-22 mm longa. Erect subshrub when young, becoming scandent and the stems up to 3-4 m long, short-hirsute. Leaves narrowly ovate to ovate, sometimes broadly so, 12.5-20 cm long, 5.0-8.8 cm wide, spreading hirsute on both surfaces, the hairs primarily concentrated on the veins on the lower surface, the veins usually red-tinged, margins coarsely dentate or serrate-dentate, apex acuminate, base truncate, broadly rounded or broadly cuneate, petioles reddish green, 3.2-5 cm long, moderately to densely hirsute, sometimes somewhat retrorsely so. Flowers (4)6 per verticillaster, sometimes the terminal one with 8 flowers, in an open, unbranched, racemose inflorescence 18-34 cm long, apparently the stem resuming vegetative growth after flowering, pedicels 9-10 mm long, sometimes on a common peduncle up to 4 mm long, moderately to densely short-hirsute, bracts ovate, the lower ones 6-11 cm long, t e upper ones 2.5-3 cm long; calyx campanulate, 8-12 mm long, green, short-hirsute on both surfaces, the hairs spreading to somewhat antrorsely appressed, the lobes 4-7 mm long, widely spreading, he margins with 1-several coarse teeth, apex acute; corolla white, ca. 19-22 mm long, short-hirsute mostly on the upper side, upper lip 6-7 mm long, the lower lip 9-12 mm long. Nutlets ca. 8-9 mm long, greenish black. NovoN 9: 280-283. 1999. This content downloaded from 157.55.39.154 on Thu, 08 Dec 2016 05:13:28 UTC All use subject to http://about.jstor.org/terms Volume 9, Number 2 1999 Wagner Hawaiian Phyllostegia 281