A new combination in Adenophorus (Polypodiaceae).

A New Combination in Adenophorus (Polypodiaceae).--Three genera of grammitid ferns (Polypodiaceae) occur in the Hawaiian Islands: Adenophorus Gaudich., Grammitis Sw., and Lellingeria A. R. Sm. & R. C. Moran (Palmer, Hawai'i's Ferns and Fern Allies, University of Hawaii Press, Honolulu. 2002). Although ali bur one of the Hawaiian species of these genera are endemic, only Adenophorus is an endemic genus, with 8-10 species (Bishop, Brittonia 26:217-240. 1974; Palmer, 2002; Ranker et al., Molec. Phylogenet. Evol. 26:337-347. 2003). Lellingeria comprises about 57 species that are mostly Neotropical with a few species in Africa and Madagascar, one endemic to French Polynesia, and one endemic to the Hawaiian Islands. Grammitis is a pantropical genus that has often been circumscribed to include 200 or more species (e.g., Parris, pp. 153-157 in K. Kubitzki ed, The Families and Genera of Vascular Plants, vol. 1. Springer-Verlag, Berlin. 1990). Primarily based on phylogenetic analyses of plastid DNA sequences, Ranker et al. (Taxon 53:415-428. 2004) found strong evidence for the polyphyly of Grammitis s.1. with the type species of the genus, G. marginella (Sw.) Sw., being a member of a small, well-supported clade of about 25 species, ali of which are characterized by having black, sclerified leaf margins, a character state that is an autapomorphy for this group of grammitid ferns and, thus, defines the clade. None of the four Hawaiian Grammitis species possess black leal margins and none were supported as members of the black-margined clade in the family-level phylogenetic analyses of Ranker et al. (2004). Thus, the Hawaiian Grammitis species should be referred to other genera. Parris (Gard. Bull. Singapore 58:233-274. 2007) included the Hawaiian G. baldwinii (Baker) Copel., G. forbesiana W. H. Wagner, and G. hookeri (Brack.) Copel. (the last also found in Fiji and Samoa) in Oreogrammitis Copel. Those three species were strongly supported with molecular phylogenetic data as a Hawaiian clade that has diverged from within a primarily SW Pacific-Malesian-SE Asian clade (Ranker et al., 2004; Ranker, unpublished data). The fourth species of Hawaiian Grammitis, G. tenella Kaulf., was not supported as a close relative of other Hawaiian Grammitis species, but was strongly supported as sister to Adenophorus (Ranker et al., 2003; Ranker et al., 2004).

Adenophorus was primarily circumscribed as a distinct genus based on the presence of putatively unique glandular, receptacular paraphyses (Bishop, 1974). Glandular paraphyses do occur on G. tenella and were noted by Wagner (Taxon 13:56-64. 1964) and Parris (pp. 81-90, in R. J. Johns, ed, Holttum Memorial Volume, Royal Botanic Gardens, Kew. 1997), but the apical cell is typically much smaller than those in Adenophorus spp. and it has never been suggested that G. tenella might be related to Adenophorus. A possible reason for this is that G. tenella possesses at least a couple of obvious features that readily distinguish it from Adenophorus spp., including a very thin rhizome (i.e., ca. < 1.5 mm in diameter vs. > 1.5 mm in Adenophorus) with leaves more separated than is found in most species of Adenophorus, and mostly glabrous leaf lamina (vs. lamina with varying densities of glandular hairs in Adenophorus). Molecular phylogenetic evidence, however, provides robust support for a sister-taxon relationship between G. tenella and the Adenophorus clade (Ranker et al., 2003; Ranker et al., 2004). Phylogenetic analyses of sequence variation for the plastid genes rbcL and atpB supported this sistertaxon relationship with 98% parsimony bootstrap support, 1.0 posterior probability Bayesian support, and Bremer support of 7 steps. The wellsupported sister group to the G. tenella + Adenophorus clade includes the monophyletic black-margined Grammitis spp. as sister to the monophyletic genus Cochlidium Kaulf. Neither of the latter two groups possess glandular, receptacular paraphyses. Thus, even though glandular paraphyses of varying morphology occur in a diversity of grammitid taxa, their presence in G. tenella and Adenophorus spp. serves as a synapomorphy for that combined clade. Because of this shared feature of glandular, receptacular paraphyses and in light of the highly robust molecular phylogenetic data, I propose the following combination in Adenophorus.

Adenophorus tenellus (Kaulf.) Ranker, comb. nav.--Grammitis tenella Kaulf., Enum. Filic. 84. 1824. TYPE.--OWahu insularum Sandwich., Chamisso s.n. (holotype, LE; photo of holotype at BISH!).

Specimens examined at BISH: HAWAIIAN ISLANDS: Kaua'i: 1895, A. A. Heller 2215; 1917, C. N. Forbes 1705K; 1969, J. Henrickson 4001; 1955, B. C. Stone 796; 1960, B. C. Stone 3343; 1983, W. Takeuchi Alakai_192. O'ahu: 1923, D. L. Topping 2647; 1984, W. Takeuchi Koolau_30; 1930, H. St. John 10615; 1932, H. St. John 11688; 1932, H. St. John 12220; 1990, T. A. Ranker et al. 1098; 1933, F. R. Fosberg 9429; 1951, A. K. Chock 206. Moloka'i: 1948, H. St. John 23419; 1987, D. H. Lorence 5469. Lana'i: 1915, G. C. Munro 470; 1935, F. R. Fosberg 12487; 1963, O. & I. Degener 30152. Maui: 1984, R. Hobdy 1990; 1976, P. K. Higashino & G. Mizuno 3098. Hawai'i: 1954, H. St. John 25395; 1990, T. A. Ranker 1117; 1989, T. A. Ranker 996; 1980, F. R. Fosberg 60552; 1995, K. R. Wood 4723.--TOM A. RANKER, Department of Botany, University of Hawai'i at Manoa, 3190 Maile Way, St. John 101, Honolulu, HI 96822.