Taxonomic Revision of the Eurasian Stipa Subsections Stipa and Tirsae (Poaceae) Author(s): Raúl Gonzalo , Carlos Aedo , and Miguel Ángel García Source: Systematic Botany, 38(2):344-378. 2013. Published By: The American Society of Plant Taxonomists URL: http://www.bioone.org/doi/full/10.1600/036364413X666615 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Systematic Botany (2013), 38(2): pp. 344–378 © Copyright 2013 by the American Society of Plant Taxonomists DOI 10.1600/036364413X666615 Taxonomic Revision of the Eurasian Stipa Subsections Stipa and Tirsae (Poaceae) Rau´ l Gonzalo,1,2 Carlos Aedo,1 and Miguel A´ ngel Garcı´a1 1Real Jardı´n Bota´nico, CSIC, Dpto. de Biodiversidad y Conservacio´n. Plaza de Murillo 2, 28014 Madrid, Spain. 2Author for correspondence ([email protected]) Communicating Editor: Lucia G. Lohmann Abstract—A comprehensive taxonomic revision of Stipa subsects. Stipa and Tirsae is presented. We analyzed the pattern of morphological variation of the taxa included in both subsections through the study of 1353 vouchers from 27 herbaria. Variation in floral and leaf morphology was further explored to revaluate taxon limits in 165 specimens using univariate analyses (Anova, Tukey test and, c2 test), and multivariate tests (principal components analysis and discriminant analysis). We found that one species of subsect. Tirsae plus three species and five subspecies of subsect. Stipa can be distinguished based on morphological characters. For each taxon, we present a dichotomous key, a list of synonyms, detailed morphometric descriptions, illustrations, and distribution maps. In addition, neotypes are proposed for S. pulcherrima var. mollis (subsection Stipa) and S. aperta (subsection Stipa), and a lectotype is proposed for S. cerariorum (subsection Tirsae). Likewise, two new combinations are proposed: Stipa subsection Tirsae (Martinovsky´) R. Gonzalo, and Stipa turkestanica subspecies macroglossa (P.A Smirn.) R. Gonzalo. Keywords—Asia, Europe, multivariate analyses, Stipa pennata, Stipa tirsa, taxonomy. The Poaceae is among the largest plant families of angio- 1970; Cope 1982; Moraldo 1986; Freitag 1985; Watson and sperms, including around 800 genera and 11,000–13,000 spe- Dallwitz 1992). However, recent morphological, anatomical cies (Soreng et al. 2007), distributed in 12 subfamilies and and molecular studies have substantially changed generic 42 tribes (Barker et al. 2001). Of the 12 subfamilies currently boundaries in the tribe (Pen˜ailillo 1996; Jacobs and Everett recognized, the Pooideae, with ca. 3,300 species is one of the 1996; Va´zquez and Barkworth 2004; Barkworth et al. 2008; largest and most important economically (Barker et al. 2001). Romaschenko et al. 2007, 2010; Cialdella et al. 2010). In par- Indeed, important crops such as barley (Hordeum vulgare), rye ticular, the circumscription of Nassella has been significantly (Secale cereale), and oats (Avena sativa) are all members of the expanded, and the genus now includes ca. 116 species, rep- Pooideae (Barker et al. 2001). This subfamily includes 13 tribes resenting the second largest genus in the tribe (Barkworth (Barker et al. 2001), of which Stipeae represents a basal line- et al. 2008). In addition, older genera have been resurrected age group, whose origin is placed after the separation of (Jarava Ruiz and Pav., Macrochloa Kunth), and new ones have Brachyelytreae. Ohwi, Lygeeae J. Presl, and Nardeae W.D.J. been described, such as Hesperostipa (M. K. Elias) Barkworth, Koch (Barker et al. 2001; Davis and Soreng 2007; Soreng et al. Austrostipa S. W. L. Jacobs & J. Everett, Celtica F. M. Va´zquez & 2007). Stipeae grasses are important components of the vege- Barkworth, Amelichloa Arriaga & Barkworth and Pappostipa tation and often the dominant grass of xeric habitats from (Speg.) Romasch., P. M. Peterson & Soreng. lowlands up to the alpine belt (Freitag 1985). These grasses The current circumscription of Stipa includes approxi- have traditionally been employed in the production of paper mately 140 species (Barkworth et al. 2008) geographically (S. tenacissima L.), but are especially important and appreci- confined to Asia, Europe and North Africa (Romaschenko ated as pasture plants for their high regeneration ability, et al. 2007; Barkworth et al. 2008). Under this circumscription, resistance against grazing, and nutritional properties. Tribe the genus is characterized by 1-flowered spikelets, and anthecia Stipeae is a well-defined monophyletic group (Pen˜ailillo 1996; that are disarticulated above the glumes, leaving a sharp- Hsiao et al. 1999; Jacobs et al. 2000, 2007), with approximately pointed callus attached at its base. The lemma is often very 21 genera (Romaschenko et al. 2010) and 400–600 species, dis- long and narrow, terete, indurate, and strongly convolute, tributed in all continents, except for Antarctica (Barkworth terminating in a prominent awn. The callus, lemma and et al. 2008; Romaschenko et al. 2007, 2010; Cialdella et al. palea are known as anthecium. The awn is unigeniculate or 2010). The tribe is characterized by a single-flowered spikelet, bigeniculate and usually twisted below the first bend. The glumes equalling or longer than the lemma, an apical awn, portion below the bend is referred to as the column, while and two or three lodicules (Clayton and Renvoize 1986). In the portion above the bend is referred to as the seta. addition, small chromosomes with a base number of X = 10–12 Stipa includes some of the most complicated taxonomic are also diagnostic (Tzvelev 1976; Freitag 1985; Romaschenko problems in Poaceae, with species often exhibiting great plas- et al. 2007, 2010). ticity in morphological characters. The lack of stable mor- Even though the limits of tribe Stipeae are well defined, the phological structures and the difficulty in establishing clear circumscription of genera within this tribe has been contro- morphological boundaries between taxa, has resulted in com- versial during the past decades. The major area of uncertainty plicated infrageneric classifications, with the creation of a is associated with the circumscription of Stipa (Jacobs et al. high number of taxa at the specific and infraspecific ranks 2007). Traditionally, the genus has been broadly circumscribed (Smirnow 1925, 1926, 1928, 1929, 1938, 1970; Martinovsky´ (Spegazzini 1901, 1925; Hitchcock 1925, 1951), encompassing 1982; Klokov and Osychnyuk 1976; Moraldo 1986; Va´zquez most of the currently accepted genera in the tribe, except for and Gutie´rrez 2011). These problems have been extensively Oryzopsis Michx., Piptochaetium J. Presl, Nassella E. Desv. and noted in the literature (Tzvelev 1974, 1976; Scholz 1985; Aciachne Benth. This traditional circumscription included ca. Freitag 1985; Strid 1991). 300–400 species of temperate and subtropical regions in both The infrageneric classification of Stipa suffered many hemispheres (Clayton and Renvoize 1986; Tzvelev 1976; Bor changes during its taxonomic history. Dumortier (1823) was 344 lemma or a lemma that is shorter than the subdorsal row as the setas; (4) ser. unigeniculate awns, and columns that are 1/10–1/8 as long two sections based on awn features: (1)the sect. first author to provide an infrageneric classification, with 2013] GONZALO ET AL: REVISION OF TWO SUBSECTIONS OF made by Martinovsky with 2 styles (Tzvelev 1976; Va mose setas with hairsglabrous longer than or (3-)4 minutely mmlemmas scabrous long, with (rarely and longitudinal ovary hairy) rowsacterized columns, by of plu- a hairs, caespitose habit, bigeniculate long awns, acuminate glumes, terete 1976; Moraldo 1986;by Va other Europeanfive subseries taxonomists (Table (Klokov 1), and a concept Osychnyuk followed and extended Barbatae Species with completelySubsmirnovia pilose awns are included inBarbatae sect. Stipa gaubae 2000; Wu and PhillipsGigantea 2006; Va 1976), whereas section are currently included under tions the sections haveonomic remained placement problematic. of the For individual example, species and sec- the limits of and short awns ( Roshev, with pointedS. glumes, shorter pennata lemmabrous than glumes, or scabrousogy: column (1) ser. and(1934), a who plumose recognized seven seta, seriesgeneric based including classification on of awn1836–1841; morphol- Steudel 1854). The first comprehensive infra- Va Tzvelev 1974, 1976; Martinovsky sequently included in sect. S. capillata with “ Pulcherrimae separated in the monotypicand sect. short ligules inTrin. the & Rupr., basal characterized by leaves. a completely This pubescent lemma taxon is currently Lessingianae history of and 1982) have remained as landmarks in the taxonomic