-A new species in the Lycopodiaceae, a firmoss, Phlegmariurus stemmermannii A.C. Madeiros & W.H.Wagner, is described and illustrated from East Maui and the island of Hawaii. A contrasting description is also given for the most closely related Hawaiian species, P. mannii (Hillebr.) W.H.Wagner. The non-strobilate Lycopodiaceae in Hawaii comprise four species and one hybrid of epiphytic, non-gemmiferous firmosses (Phlegmariurus) and five species and five hybrids of terrestrial or epipetric, gemmiferous firmosses (Huperzia). Of the former, only one of the taxa (Phlegmariurus filiformis (Sw.) W.H. Wagner) lacks pendent tassles of sporophylls, and the remainder possess the tassles. The rarest of the tassled firmosses is Mann's firmoss (P mannii). Very few collections have been made of it, all from the mountains of West and East Maui, and Hawaii. It has been studied intensively in the field by Medeiros and Hobdy over the past decade, and there seems to be no question regarding its species status. During studies of the collections at the Bishop Museum in 1993, however, W. H. Wagner recognized an unusual single specimen from Hawaii that appeared to be a new species. Subsequently, plants with the same characteristics were discovered by Medeiros in Haleakala, in East Maui. With these additional specimens it was possible to confirm the distinctive features of the new lycopod, and the results of these studies are reported here. The two species dealt with in this paper belong to 11gaard's Myrsinites subgroup, Slender to delicate plants, often with red stems, usually decussate or subdecussate leaves throughout. Leaves of the basal divisions irregular in size or shape, usually not overlapping continuously (0llgaard 1987), with approximately a dozen species, all in tropical America, except for those in Hawaii. The Hawaiian species may be recognized by the fact that the sterile portions of the shoots are relatively short, usually considerably less than 15 cm, and the fertile or partially fertile tassles are usually long, up to 25 cm, Author for correspondence. This content downloaded from 157.55.39.237 on Thu, 07 Jul 2016 05:04:56 UTC All use subject to http://about.jstor.org/terms AMERICAN FERN JOURNAL: VOLUME 86 NUMBER 3 (1996) except in young plants. They grow on rough-barked trees, mostly Acacia koa, 3 meters or less from the ground. The generic names used here are those discussed by Wagner and Beitel (1992). The following key separates these two species (see also Table 1): Fertile tassles branching angles mostly 70?-140?; ultimate fertile branches 1.0-1.5 mm thick; sporophylls broadly rounded to slightly pointed, mostly short-ovate, 1-2 mm long; sterile basal portions of stem bright red 1. Phlegmariurus mannii Fertile tassles branching angles mostly 10?-50?; ultimate fertile branches 1.5-2.2 mm thick; sporophylls more pointed, mostly triangular, 1.5-2.5 mm long; sterile basal portions of stems green to pale yellow 2. Phlegmariurus stemmermanniae 1. Phlegmariurus mannii (Hillebr.) W.H. Wagner in W.H. Wagner, Jr., F.S. Wagner, & T. Flynn, Contr. Univ. Michigan Herb. 20:241. 1995 (Figs. 1, 2).Lycopodium phlegmaria L. var. mannii Hillebr., Fl. Hawaiian Isl. 645. 1888.-Lycopodium mannii (Hillebr.) Skottsb.-TYPE: Hawaii, West Maui, mountains above Malaea Bay, Mann & Brigham 506 (CU; isotype BISH). Pendent epiphyte on bark of trees. Sterile basal stem red. Intervals between basal sterile leaves along a row (typical trophophylls) remote, 2-9 mm apart. Sterile leaf tip indurated, apiculum mostly sharp, 0.2-0.3 mm long. Sterile to fertile branch transition mostly abrupt. Length of fertile, terminal branchlets 0.5-8 cm (mostly less than 3 cm). Maximum number of fertile terminal branches for a whole shoot 16-45. Branching angle of first 0.5 cm of fertile branches spreading widely, 70?-140?. Basal 1.5-3.5 cm of fertile branches with pronounced curvature, becoming straighter and more parallel distally. Sporophylls (with visible sporangia) 1.0-2.0 mm long, mostly rounded apically to slightly pointed, equal to or slightly shorter than exposed sporangia. Thickness of branches (with visible sporangia) 0.8-1.1 mm. Other Collections: HAWAII. Hawaii. NW of Papaloa, Captain Cook, Kona, epiphytic on giant koas at 1525 m, Degener 20330 & Murashigu (BISH-2 sheets). East Maui. Above W Rim of Manawainui Canyon Kaupo Maui, crotch of Acacia koa tree 2.5 m above ground, many young plants growing together to form a dense mat 0.6 m across, sporophylls sometimes root when touching suitable sites, 1300 m, Hobdy 1178 (BISH); Kahikinui, Manawainui Gulch, in rough scaly bark of an old Acacia koa tree in a rich native forest remnant, 1.5 m above the ground, 1600 m, Hobdy 2273 (MICH-2 sheets); S slope of Haleakala, Manawainui Gulch, 6 plants seen growing on two Koa trees, 1600 m, Medeiros 310 (BISH); W side of Nuanaloa Stream, Kipahulu, vegetation: Athyrium, Sadleria, Acacia, Cheirodendron, and Metrosideros, 1300 m, Higashino & Mizuno 3140 (BISH). West Maui. Haelaau, on tree trunk, 885 m, Ewart & Swezey 135 (BISH, US, UC); Lihau Peak, epiphytic on ohia tree in fairly dense shady understory 3 m above ground, 1200 m, Hobdy 22422 (BISH). 2. Phlegmariurus stemmermanniae A.C. Medeiros & W.H. Wagner, sp. nov. (Figs. 3, 4).-TYPE: Hawaii, Maui, SE slope of Haleakala, Kaapahu, epiphytic on Syzygium sandwicense tree, 1150 m, 1995, Medeiros & Chimera 2220 (MICH). Differt a Phlegmariuro mannii caulibus sterilibus omnibus viridibus ad caules fertiles gradatim mutantibus, foliis confertioribus 1-2 mm inter se distan90 This content downloaded from 157.55.39.237 on Thu, 07 Jul 2016 05:04:56 UTC All use subject to http://about.jstor.org/terms MEDEIROS ET AL.: A NEW HAWAIIAN PHLEGMARIURUS