Eleocharis mamillata - Distribution and Infraspecific Differentiation Author(s): Thomas Gregor Source: Folia Geobotanica, Vol. 38, No. 1 (Mar., 2003), pp. 49-64 Published by: Opulus Press Stable URL: http://www.jstor.org/stable/25133950 Accessed: 01/12/2009 06:45 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=opulus. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Opulus Press is collaborating with JSTOR to digitize, preserve and extend access to Folia Geobotanica. http://www.jstor.org Folia Geobot?nica 38: 49-64, 2003 ELEOCHARISMAMILLATA - DISTRIBUTION AND INFRASPECIFICDIFFERENTIATION Thomas Gregor Hochschule Vechta, Driverstra?e 22, D-49377 Vechta, Germany; fax +49 4441 15460, e-mail thomas.gregor@uni-vechta. de Abstract: Eleocharis mamillata is a widespread species in the temperate zone of Eurasia and North America. Populations in mountainous areas of Europe and Asia (the Pyrenees, Alps, Carpathians, Balkans, Ural, Caucasus, Altai) can be separated as subspecies austriaca differing mainly by the stylopodium shape from the nominate subspecies. Clear morphological criteria to create a separate infraspecific taxon in East Asia could not be found. Keywords: Cyperaceae, Eleocharis austriacay E. ussuriensis, E. leptostylopodiata INTRODUCTION Most problems concerning the central and north European species of Eleocharis subser. Eleocharis (= E. subser. Palustres SVENSON) seemed to be solved by the exhaustive work of STRANDHEDE (1961, 1966). Only Eleocharis mamillata subsp. austriaca remained somewhat unclear. During a survey of E. mamillata in Hesse/Germany (GREGOR & BARTH 1998) some populations could neither be ascribed to subsp. mamillata nor to subsp. austriaca. Therefore, it seemed worthwhile to investigate the taxonomic value of the subsp. austriaca. Eleocharis austriaca and related taxa HAYEK (1910) mentions weaker palisade parenchyma, grey-green culms, always 6 perigon bristles, and the base of style (stylopodium) not clearly separated from the nut in the protologue of Eleocharis austriaca as differentiating characters from E. palustris. E. austriaca was separated by him from E. mamillata by stiffer, grey-green culms, 15-20 vascular bundles, a better developed palisade parenchyma, and a higher stylopodium (swollen lower part of the style attached to the fruit). Except for the culm colour and bristle number these characters were confirmed by later authors (e.g. STRANDHEDE 1966). Material distributed in the "Flora stiriaca exsiccata" (collected by Karl Fritsch) on which the name E. austriaca is based partly does not belong to E. austriaca. According toWALTERS (1953), the sheets in Lund (L) and G?teborg (GB) are mixed collections of E. austriaca and E. mamillata. Two sheets in Berlin (B), one in London (BM), and one inVienna (W) belong to E. mamillata s.str. One sheet in Graz (GZU 014585) belongs to E. austriaca, another one (GZU 014586) contains E. austriaca and E. mamillata s.str. The lectotype in Helsinki (H) selected byWALTERS (1953) is in accordance with the protologue, except for the culm-colour (light green) and the number of bristles (mostly 5). 50 T. Gregor BEAUVERD (1921) described Eleocharis benedicta from Lac B?nit in the French Alps south of Lake of Geneva. STRANDHEDE (1966) studied material from the type locality and considered it to belong toE. mamillata subsp. austr?aca. Beauverd was not aware of the close relationship between E. benedicta and E. mamillata, erroneously attributing to the latter persistent bracts. E. austr?aca is not mentioned by him. The shape of the stylopodium of E. benedicta ranges, according to BEAUVERD (1921), from less high than broad to as high as broad. Inmaterial from the type locality STRANDHEDE (1966: 108) measured a stylopodium with a length of 0.5 and a width of 0.4 mm. My own measurements of a specimen from the type locality revealed a ratio of 1.07 : 1 (see Appendix). According to the protologue the stylopodium shape is in the intermediate range between subsp. mamillata and subsp. austr?aca. So, E. benedicta should not be considered synonymous with?. austr?aca. If this is accepted, the first combination in the rank of subspecies for the taxon with high stylopodia would be Scirpus palustris subsp. benedictus (DOUIN 1931). FRITSCH ( 1926) placed E. austr?aca together with other "grey-green forms" of E. palustris s.l. under E. glaucescens (WILLD.) SCHULT. The holotype of Scirpus glaucescens in the Willdenow-herbarium in Berlin (B) consists of an immature plant with two spikes. "Habitat in America boreali" ismarked on the sheet. ZINSERLING (1935) did not mention E. austr?aca, but described two species similar to E. mamillata: E. ussuriensis from the Russian Far East with short conical stylopodia (height/width: 1.2-1.5/1) and E. leptostylopodiata from the Ural with narrow conical stylopodia (height/width:2-3/1). WALTERS (1953) confirmed most of Hayek's characters of E. austr?aca, stressing its intermediate position between E. mamillata and E. palustris. He found new characters differentiating E. austr?aca and E. mamillata from E. palustris: the number of epidermal cell rows between fibre-rows (= collenchyma strands) as 3-5 versus 1-3, and the form of the stomata: guard cells longer than subsidiary cells (short side convex) versus guard cells shorter than subsidiary cells (short side concave). E. leptostylopodiata is regarded as "possibly identical" to E. austr?aca, later (WALTERS 1959) as synonymous. STRANDHEDE (1961, 1966) found the number of achenes per centimetre in the spike helpful for the differentiation of the subspecies: approx. 60 in subsp. austr?aca versus approx. 42 in subsp. mamillata. The most important character to distinguish the two subspecies proved to be the stylopodium shape: mamillate in subsp. mamillata with amean height-width ratio of 0.75 : 1; elongated triangular in subsp. austr?aca with a mean height-width ratio of 1.5 : 1. E. leptostylopodiata and E. ussuriensis are regarded as synonyms of E. mamillata subsp. austr?aca. EGOROVA (1976) regarded E. austr?aca and E. leptostylopodiata as synonymous. In the Russian Far East, northern China, Japan, and Korea E. mamillata subsp. ussuriensis is differentiated from the nominate subspecies by short conical broad-based stylopodia. Eleocharis mamillata var. cyclocarpa KlTAGAWA is regarded as synonymous with E. mamillata subsp. ussuriensis. Distribution and ?nfraspecific differentiation of Eleocharis mamillata 51 MATERIALAND METHODS Present study is based on about 600 specimens of Eleocha?s mamillata from the public herbaria and private collections mentioned in the Acknowledgements. The following characters were recorded for each specimen: length and width of achene and stylopodium, number of hypogynous bristles, number of vascular bundles of a fertile stem and number of achenes per cm in the spike (receptacle density). Five ripe fruits (in some cases only 3) from one specimen were measured. The number of vascular bundles and the stem-diameter were measured once, at a height of about 2/3 of the stem. The achene-length was measured without a short stalk, which is sometimes present. Two-cleft or three-cleft bristles were counted as 2 or 3 bristles. Receptacle density was only measured on spikes that had shed their fruits and glumes. This state is only reached inmature spikes, collected late in season. Most herbarium specimens have been collected at an earlier state of development. Correlations between parameters were tested by Spearman's correlation coefficient (rs). Using a graphic adaptation ("full width at half maximum") described by BRANDT (1999) normal-distributions were calculated from the data of the stylopodium shape. Principal components analysis (PCA) was performed using SPSS. The maps were produced with BRAHMS (Botanical Research And Herbarium Management System) and M?SICA. RESULTS AND DISCUSSION Principal components analysis The first three principal components (PCs) explain 78% of the total variance (46.8%, 19.6%, and 11.5% for PCI, PC2, and PC3 respectively). PCI has high positive loadings for stylopodium height/stylopodium width, fruit density, number of vascular bundles, and stylopodium height and high negative loadings for stylopodium width, stylopodium width/achene width and number of bristles; PC2 has high positive loadings for achene height and achene width (Fig. 1). The scatter diagram of the first two components (Fig. 2) distinguishes subsp. mamillata and subsp. austr?aca as differentiated by stylopodium shape (see below). The two groups are connected by intermediates. Parameters with high loadings on PCI will be discussed further. Height (1.31 mm ? 0.1 s.d.) and width (1.13 mm ? 0.09 s.d.) of the achenes that have high positive loadings on PC2 are not correlated with the stylopodium shape. Of all parameters, only the stylopodium shape (stylopodium height by stylopodium width) shows a bimodal distribution with peaks at about 0.725 and 1.4 (Fig. 3). However, the stylopodium shape generally has a high variation. In a cultivated specimen from the Rh?n in Thuringia/Germany 120 measurements had an arithmetic mean of 1.37 with a standard deviation of 0.16 and extreme values of 1.04 and 1.79.