Rediscovery and Assessment of Stenogyne sherffii Degener (Lamiaceae) Warren L. Wagner Department of Botany, MRC-166, National Museum of Natural History, Smithsonian Institution, Washington, l).C. 20560, U.S.A. [email protected] Stephen G. Weller Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92717, U.S.A. [email protected] ABSTRACT. Stenogyne sherffii 0. Degener from the (1943) as S. sherffii from the northern Ko‘olau Moun¬ Ko‘olau Mountains, 0‘ahu, Hawaiian Islands, was tains, 0‘ahu. Subsequently, we have propagated it treated as synonymous with the more common spe¬ from a stem cutting in the greenhouse at the Uni¬ cies from the WaPanae Mountains, S. kaalae Wa- versity of California, Irvine. For comparative pur¬ wra, in the most recent revision of the genus by poses we have also grown S. kaalae Wawra, which Weller and Sakai in 1990. A single population of occurs at a number of localities in the Wai‘anae about five plants of this entity was rediscovered in Mountains, 0‘ahu (with a single collection made in 1994. A plant was propagated from a stem cutting 1852 from Nu‘uanu Pali in the southern Ko'olau in the greenhouse at the University of California, Mountains). The plants described as Stenogyne sherf¬ Irvine. Comparison to plants of S. kaalae grown in fii are closely allied to S. kaalae, and this taxon was the same greenhouse and herbarium material shows included with S. kaalae by Weller and Sakai (1990: that die rare Ko‘olau plants are distinct in several 838) based on study of the type. Our greenhouse characters, especially subentire vs. serrate leaves. study shows that the Ko‘olau Mountain plants differ We here recognize this taxon as a subspecies of S. in several characters, although the relationship to S. kaalae because of the clear species synapomorphy kaalae is very close. The morphological distinctions of very dark maroon corolla color and the geograph¬ coupled with the geographical separation of about ical separation of the two taxa. 30 km support recognition of the Ko‘olau plants as a subspecies of S. kaalae. Stenogyne Bentham is an endemic Hawaiian ge¬ Stenogyne species on younger islands of Maui nus of vines in the Lamiaceae consisting of 21 spe¬ and especially Hawai‘i are more polymorphic than cies (Weller & Sakai, 1990; Wagner & Weller. 1991), the species on the older islands of 0‘ahu and with greater diversity on younger than on older is¬ Kaua‘i (Weller & Sakai, 1990). Similar patterns of lands. Hawai‘i (8 species) and Maui (9 species) have greater polymorphism within species on the youn¬ the greatest diversity, while lower diversity occurs on ger islands occur in a number of other genera in¬ Moloka‘i (3 species), Lana‘i (2 species), 0‘ahu (2 cluding Cyrtandra .1. B. Forster & G. Forster (Ges- species), and Kaua‘i (3 species). The reduced lower corolla lip, exserted stamens, abundant nectar pro¬ neriaceae), Labordia Gaudichaud (Loganiaceae), duction, lack of floral odor, and long falcate corollas Lysimachia L. (Primulaceae), Melicope J. R. Forster of some Stenogyne species provide circumstantial & G. Forster (Rutaeeae), Myrsine L. (Myrsinaceae), evidence for pollination of Stenogyne by honeycreep- and Phyllostegia (Lamiaceae). Extinction of inter¬ ers (Weller & Sakai, 1990). In the Hawaiian genus mediate forms and evolution of novel forms on older Phyllostegia Bentham, with which Stenogyne and islands, as well as increasing isolation resulting Haplostachys (A. Gray) Hillebrand share a common from erosion and dissection of habitats, are likely ancestor, the presence of a sweet floral fragrance explanations for the greater ease in delimiting spe¬ among some species and the expanded lower corolla cies on the older Hawaiian Islands. These factors lip and predominant white coloration indicate pol¬ could explain the patterns of variability seen in lination by insects (Weller & Sakai, 1990). Stenogyne and other genera, where more narrowly After the publication of the treatment of Stenogyne distributed, less polymorphic species are found on by Weller and Sakai (1990), J. Obata rediscovered a the older islands. Stenogyne sherffii is an example small population of the plant described by Degener of a species where geographic isolation has led to Novon 9: 448-449. 1999. Volume 9, Number 3 Wagner & Weller 449 1999 Stenogyne sherffii well-defined, through modest, differentiation from stems usually pubescent; pedicels 4—7 mm long .subsp. kaalae S. kaalae. In contrast, differences among popula¬ tions found on the island of Hawaii may he of Stenogyne kaalae Wawra subsp. sherffii (0. De- greater magnitude, but lack consistency on a geo¬ gener) W. L. Wagner & Weller, comb, et stat. graphic basis. Lack of consistency in the distribu¬ nov. Stenogyne sherffii 0. Degener, Brittonia 5: tion of characters prevents recognition of infraspe- 58. 1943. TYPE: Hawaiian Islands [U.S.A.]. cifie taxa within these species and provides the 0‘ahu: [Ko‘olau Mountains], Kawailoa, rationale for use of a broadly defined species for Pe‘ahinai‘a trail, 28 Apr. 1940, 0. Degener & many of the Stenogyne taxa found on the island of Ordonez 12999 (holotype, NY; isotype, NY). Hawai‘i. Comparison of several closely related taxa of Seandent vines, climbing or sprawling and root¬ Stenogyne illustrates patterns of variation related to ing at the nodes; stems 2.5—6 m (in cultivation), island age that require different taxonomic ap¬ quadrangular, glabrous. Leaves glossy, coriaceous, proaches and demonstrate why species-level rec¬ lanceolate, the blades 8—12 cm long, 2—3.5 wide, ognition is given in most of these cases, while sub¬ antrorsely strigulose along the adaxial midvein, oth¬ species level is used for S. sherffii. Stenogyne erwise glabrous, margins inconspicuously serrulate, macrantha Bentham and S. scrophularioides Ben- apex acute to weakly acuminate, base cuneate, pet¬ tham, two polymorphic species from the island of ioles 1-2 cm long. Flowers (3)5 per verticillaster, Hawai‘i, are very distinct in some areas in both sometimes some of them on a peduncle up to 2—5 vegetative and floral characters, but show consid¬ mm long, pedicel 2-5 mm long, retrorsely strigu¬ erable morphological overlap in other areas. Pop¬ lose; calyx nearly radially symmetrical, narrowly ulations that are intermediate may result from areas campanulate, 9-15 mm long at anthesis, green or of secondary contact or represent the extremes of tinged purple, glabrous, the teeth linear-lanceolate, variation in a recently diverged ancestral species. 5—8 mm long; corolla very dark maroon, hispidu- Without extensive study, these hypotheses cannot lous externally, the hairs weakly antrorse, the mar¬ be differentiated, and at present recognition of two gins and inner surfaces glandular puberulent, the broadly defined species captures the essence of tube mostly straight, curved slightly at the throat, variation in these entities. In contrast, differentia¬ 11—12 mm long, upper lip 9—10 mm long, lower lip tion is geographically and ecologically well marked 2-3 mm long. Nutlets 4 mm long, fleshy, dark pur¬ for a morphologically distinct pair of species from ple. East Maui; the extinct S. haliakalae Wawra, which Distribution. Known only from the Pe‘ahinai‘a occurred at lower and drier elevations on the south Trail in the northern part of the Ko‘olau Mountains, slopes of Haleakala, and S. rotundifolia A. Gray, a 0‘ahu, from only two collections (1940 and 1994). species still common at higher, wetter elevations on Apparently there is only a single extant population the north slopes of Haleakala. A third pattern of with perhaps five individuals (J. Obata, pers. variation is exemplified by S. purpurea H. Mann comm.). and S. kealiae Wawra, both endemic to Kaua‘i. These species differ only in vegetative characters, Specimen examined. HAWAIIAN ISLANDS [U.S.A.]. but rare and narrowly distributed S. kealiae occurs Oahu: Ko'olau Mountains, Pe‘ahinai'a Trail, 1994, Obata sympatrically with the widespread S. purpurea, and s.n. (US), cultivated in 1997 from Obata s.n. (BISH, F, K, US). therefore they are considered distinct species. Sten¬ ogyne sherffii and S. kaalae, which like S. kealiae Acknowledgments. We appreciate the helpful and S. purpurea on Kaua‘i differ only in vegetative comments by R. Shannon and two anonymous re¬ characters, are completely allopatric in the same viewers on the manuscript, and John Obata for pro¬ habitat type. The minor, strictly vegetative differ¬ viding us with cuttings to propagate in the green¬ ences and the allopatric distribution of S. sherffii house. and 5. kaalae provide the justification for subspe¬ cific recognition. Literature Cited Degener, 0. 1943. Stenogyne sherffii, a new mint from Ki n to thk Sfbspkciks ok Sm\o(;v\E kaaiak Hawaii. Brittonia 5: 58—59. la. Leaf margins inconspicuously serrulate, the Wagner, W. L. & S. G. Weller. 1991. Resurrection of a blades 8—12 cm long, 2—3.5 cm wide, coria¬ Kaua‘i Stenogyne: S. kealiae. Pacific Sci. 45: 50—54. ceous; stems glabrous; pedicels 2—5 mm long Weller, S. G. & A. K. Sakai. 1990. Stenogyne. Pp. 831 — .subsp. sherffii 843 in W. L. Wagner, I). R. Herbst & S. H. Sohmer, lb. Leaf margins serrate, the blades 4.2-7.7 cm Manual of the Flowering Plants of Hawai'i. Univ. Hawaii long, 1.7-2.9 cm wide, thin and membranous; Press and Bishop Museum Press, Honolulu.