J. Jpn. Bot. 87: 169–186 (2012) Delineation of Schoenoplectiella Lye (Cyperaceae), a Genus Newly Segregated from Schoenoplectus (Rchb.) Palla Eisuke hayasaka Fukui Botanical Garden, Echizen, Fukui, 916-0146 JAPAN E-mail: [email protected] (Accepted on March 25, 2012) Schoenoplectiella Lye, a genus segregated from Schoenoplectus (Rchb.) Palla, is accepted with expanded circumscription to include all the species formerly placed in Schoenoplectus sectt. Actaeogeton (Rchb.) J. Rayn. and Supini (Cherm.) J. Rayn. A revised description of Schoenoplectiella is provided and all the 50 species included in the genus are listed with 34 new combinations for the species, varieties, and hybrids. Two sections, Schoenoplectiella sectt. Schoenoplectiella and Actaeogeton (Rchb.) Hayasaka are recognized with 25 species for each, and a key to and descriptions for the sections are given. Morphological characters that define Schoenoplectiella and its sections, as well as those that distinguish the genus from allied genera, are discussed. Key words: Cyperaceae, generic circumscription, infrageneric classification, morphology, new combination, Schoenoplectiella, Schoenoplectus, Scirpus. Schoenoplectus (Rchb.) Palla, one of the Ficinia Schrad. with 74 species and Isolepis R. segregates of Scirpus L. s. l., has been widely Br. with 74 species (Muasya and Simpson 2002, accepted since 1980’s in the floras of various Govaerts and Simpson 2007). regions of the world (Lye 1997, Kukkonen Species of Schoenoplectus show a 1998, Simpson and Koyama 1998, Smith considerable wide range of variation in their 2002, Liang et al. 2010), or in individual habit and morphology of both vegetative and taxonomic accounts (Wilson 1981, Strong 1994, reproductive organs. They can range from a Gordon-Gray 1995, Pignotti 2003, Egorova dwarf, tufted annual up to 5 cm high growing in 2005). Among the Scirpus segregates, either seasonally wet habitats, to a large, rhizomatous Actinoscirpus (Ohwi) R. W. Haines & Lye or perennial up to 350 cm high growing in Bolboschoenus (Asch.) Palla is merged into permanently wet, freshwater or brackish Schoenoplectus by some authors (Koyama 1978, habitats. Interspecific variation in morphological Lye 1997), but Schoenoplectus as excluding characters is remarkable especially in the shape these two genera is more frequently accepted of rhizomes, leaf blades, inflorescences, glumes, in recent years (Govaerts and Simpson 2007). perianth segments, nutlets, and in the presence Schoenoplectus in the latter sense comprises 77 or absence of nodes on a culm (Smith and species worldwide ranging from the subarctic to Hayasaka 2001). the tropics (Hayasaka 2002). The genus is now To grasp the species relationships within the largest of the Scirpus segregates, exceeding this large and polymorphic genus, attempts —169— 170 植物研究雑誌 第 87 巻 第 3 号 2012 年 6 月 have been made to establish an infrageneric Young at University of Oklahoma (Unpublished system in Schoenoplectus. Oteng-Yeboah (1974) data, pers. comm. 2001–2002) used ITS and recognized and provided a key to the three trnL sequences for the infrageneric phylogeny subgenera Schoenoplectus, Actaeogeton (Rchb.) of Schoenoplectus, and indicated that the genus Oteng-Yeb., and Malacogeton (Ohwi) Oteng- is represented by two well-supported clades Yeb. His subgeneric system is recently adopted that are not sister to each other: one with the in the Schoenoplectus treatment of Pignotti species of the sections Schoenoplectus and (2003). Raynal (1976b) provided a monograph Malacogeton, the other with those of the sections of the section Supini (Cherm.) J. Rayn. with 21 Actaeogeton and Supini. Each of the above four species mainly from Africa and Madagascar, and sections recognized by Smith and Hayasaka he recognized the four sections Schoenoplectus, (2001, 2002) is supported as monophyletic in Actaeogeton (Rchb.) J. Rayn., Pterolepis her work. Molecular phylogeny within Japanese (Schrad.) J. Rayn., and Supini (Raynal 1976a, b, Schoenoplectus presented by Yano and Hoshino 1977). Raynal’s sectional treatment is followed (2005) also shows the monophyly of the two by Haines and Lye (1983) and Kukkonen sections Schoenoplectus and Actaeogeton. (1998). Smith and Hayasaka (2001, 2002) In their study, Japanese Schoenoplectus was partly accepted Raynal’s sectional treatment resolved into two clades, one with the species of and applied it also to the North American and the section Actaeogeton, the other with those of eastern Asian species, recognizing the four the sections Schoenoplectus and Malacogeton. sections Schoenoplectus (including Pterolepis), Deliberating on the results of these studies that Actaeogeton, Malacogeton (Ohwi) S. G. Smith indicate the polyphyly of Schoenoplectus as & Hayasaka, and Supini. Their infrageneric well as the monophyly of the four sections, the system is adopted in the Schoenoplectus genus should be divided into two genera, with treatments of Smith (2002) and Egorova (2005), the circumscription of the sections maintained as and is also used as a basis for discussion in the currently recognized under Schoenoplectus (s. molecular phylogenetic studies of the genus l. with 77 spp.). A solution could be delimiting (Yano and Hoshino 2005, Jung and Choi 2010). Schoenoplectus (s. s.) with 27 species classified Molecular phylogenetic studies in recent into the two sections Schoenoplectus and years show that Schoenoplectus as currently Malacogeton, and simultaneously establishing delimited is polyphyletic. In the suprageneric a new genus with 50 species classified into two phylogeny of Cyperaceae using rbcL sequences sections that correspond to Schoenoplectus sectt. (Muasya et al. 1998, Simpson et al. 2007), Actaeogeton and Supini. Schoenoplectus was resolved into two clades, Based on the rbcL suprageneric phylogeny one with S. lacustris (L.) Palla of the section of Muasya et al. (1998), Lye (2003) described Schoenoplectus and Actinoscirpus grossus (L. the new genus Schoenoplectiella Lye, which f.) Goetgh. & D. A. Simpson, the other with S. includes 26 species formerly placed in articulatus (L.) Palla and S. junceus (Willd.) Schoenoplectus. The greater part of these species J. Rayn. of the section Supini, as sister to are comparatively small, amphicarpous annuals Eleocharis. Muasya et al. (2009) analyzed eight of Africa and Madagascar. In the phylogenetic species of Schoenoplectus in their rbcL and tree presented by Muasya et al. (1998), only trnL-F phylogeny, showing the genus resolved two species of Schoenoplectiella, S. articulata into two strongly supported clades, one with and S. juncea are included, the former of which the species of the section Schoenoplectus as was designated as the type of the genus (Lye sister to Actinoscirpus, the other with those of 2003). Lye (2003) apparently intended to give the sections Actaeogeton and Supini. Laura A. a generic status to Schoenoplectus sect. Supini June 2012 Journal of Japanese Botany Vol. 87 No.3 171 because his key to distinguish Schoenoplectiella Schoenoplectus sect. Actaeogeton, which is from Schoenoplectus, as well as his description an acceptable solution to the taxonomy of of the new genus, refers to the morphology Schoenoplectus s. l. However, Schoenoplectiella and habit of the species in the section (Raynal would then be a comparatively large genus 1976b). Out of the 26 species that Lye (2003) widespread in the world that needs a taxonomic included in Schoenoplectiella, 23 are those of revision. The description of Schoenoplectiella Schoenoplectus sect. Supini (Raynal 1976b, should be revised with a close examination Hayasaka 2009). The remaining three species, of morphological characters that delimit the however, are those of Schoenoplectus sect. genus, and the generic circumscription should Actaeogeton (Smith and Hayasaka 2001, be clarified with an enumeration of the included 2002). They are Schoenoplectiella purshiana, species worldwide. In addition, an infrageneric non-amphicarpous annual of eastern North system is needed because Schoenoplectiella America, S. juncoides, non-amphicarpous is to be composed of all the species of perennial of Asia and the Pacific Islands, and S. Schoenoplectus sectt. Actaeogeton and Supini, wallichii, non-amphicarpous annual of eastern which are monophyletic groups respectively, as and southern Asia. Because the habit of these well as distinguishable from each other by their species is inconsistent with the definition of morphology and habit (Raynal 1976b, Smith Schoenoplectiella as amphicarpous annuals, Lye and Hayasaka 2001, 2002). This paper addresses (2003) put them into the new genus presumably these problems. being unaware of their habit. Jung and Choi (2010) presented molecular Morphological characters of Schoenoplectiella phylogeny of Scirpus s. l. of Korea using ITS and Morphological characters that define rbcL sequences. Nine species of Schoenoplectus Schoenoplectiella and distinguish it from s. l. were included in their phylogenetic analysis, Schoenoplectus s. s. are those shared between in which the genus was resolved into two clades Schoenoplectus (s. l.) sectt. Actaeogeton that are not sister to each other. The smaller and Supini. The distinguishing characters of of these clades consists of the representatives Schoenoplectiella include the shape of rhizomes, from Schoenoplectus sectt. Schoenoplectus and culm arrangement, presence or absence of nodes Malacogeton, as sister to Actinoscirpus, while on a culm, shape of glumes, presence or absence the larger one consists of the representatives of