Allium) in Saskatchewan
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PLANTS TAXONOMY OF WILD ONIONS (ALLIUM) IN SASKATCHEWAN Hyeok Jae Choi12, Catherine Peters3, J. Hugo Cota-Sanchez23 division of Forest Biodiversity and Herbarium (KH), Korea National Arboretum, Pocheon, Gyeonggi 487-821, Korea department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2 3W. P. Fraser Herbarium (SASK), University of Saskatchewan, Saskatoon, SK, S7N 5A8; E-mail: <[email protected]> Onions (Allium species) rank second in according to Raven and Axelrod (1978), economic value after tomatoes in the list Allium has been present in the New of cultivated vegetable crops worldwide.1 World since at least the Tertiary Period.9 For generations, humans have consumed Approximately 1/6 of the world’s Allium over 20 Allium species other than the diversity is represented in North America cultivated garden onion (A. cepa L.).2 Both north of Mexico, that is, about 96 species, Old and New World Allium members are of which 12 are known from Canada.1011 becoming popular worldwide, including edible and culinary species, e.g., Chinese Several criteria have been used in chives (A. tuberosum Rottl. ex Spreng.J Allium classification. Among these, and attractive ornamental plants, such sexuality of flowers, structure and shape as nodding onion (A. cernuum) and giant of the underground parts (including onion (A. giganteum Regel). Similarly, rhizome and bulb), anatomical features consumers and researchers alike are of root, leaf, scape, and ovary, as well more aware of the health benefits and as basic chromosome number have been medical properties of alliums.3 Despite the valuable at the subgeneric and sectional cultural, economic, nutritional, and health levels.7’1012-15 In turn, shape and size of significance of Allium in human society, floral organs, such as perianth, filament, to date, its taxonomy remains complex pistil, capsule, and seed in addition to due to the proliferation of synonyms somatic chromosome number have and disagreement regarding taxonomic taxonomic significance at the specific characters used in species boundaries. level.10’16’17 In fact, the complex taxonomic history of Allium involves 1400 specific epithets, In the past, the Canadian prairie some of which have been synonymised,4 landscape of the provinces of Alberta, but no comprehensive generic monograph Saskatchewan (SK), and Manitoba has been compiled since that of Regel encompassed extensive grasslands, (1875).5 aspen parklands, and abundant wetland areas, all supporting a rich diversity Allium is widely distributed only in the of native biota.18 However, in the last Northern hemisphere, especially in the decades, large prairie areas have been temperate regions of Eurasia.6-8 The cleared and converted to cropland. genus includes over 800 species, and Lamentably, the prairies now form the 146 Blue Jay largest expansion of agricultural land leaf blade and a scape of a floriferous in Canada and represent one of the culm were used for observation of cross- most human-altered and fragmented sections. Leaf and scape tissues, fixed landscapes in the country.18-20 In addition in 70% ethanol, were hand-sectioned, to hosting unique prairie ecosystem stained with safranin, washed with distilled biodiversity, the province of SK reportedly water, observed, and photographed using has numerous native plants, including a TESSOVAR Photomacrographic Zoom five alliums, namely A. schoenoprasum System with a Nikon D100. var. sibiricum, A. geyeri var. geyeri, A. textile, A. cernuum, and A. stellatum,1121 A map depicting the distributional range Among these, A. geyeri var. geyeri is was prepared for each species (Fig. 1) included in SK’s rare and endangered based on herbarium specimens. The plant list, in addition to A. cernuum and maps were generated using a customized A. schoenoprasum.2^22 map development tool especially designed and based on the open- Although Harms (2003) provided source code Google™ Maps API on-line an assessment regarding rarity development tool. The mapping software status of species in SK,21 a formal and data used can be found at the W. P. taxonomic scheme including typification, Fraser Herbarium (SASK) website (http:// nomenclatural history, and synonyms is herbarium.usask.ca). A data table of lacking. It should be mentioned, however, Allium locations for SK was generated. that Scoggan (1978), Boivin (1979), and When latitude and longitude were not Budd (1987) treated all Allium species in provided on the voucher specimens, SK, although not with the thoroughness the coordinates were calculated based of a detailed taxonomic monograph.23-25 on the locality information using the Here, we present a taxonomic treatment Natural Resources Canada on-line Atlas of Allium in the province based on the of Canada reference maps (http://atlas. combination of quantitative and qualitative nrcan.gc.ca/site/english/maps/topo/map). data from vegetative and reproductive Once the data table was linked to the characters. The goals of this study were mapping program, the maps were plotted. to expand the current knowledge of The Google™ map initially presented the morphology and distribution and to through the mapping program had the provide a taxonomic key for the species. geographic boundaries of Canada. This study provides sound foundations for Afterwards, it was imported into Adobe updating provincial taxonomic treatments Photoshop 7.01 as a JPEG graphic, and of Allium and the family Liliaceae. the boundaries were removed so that only SK remained. Materials and Methods This study is based on specimens of Results and Discussion collections from the following herbaria: The following taxonomic treatment is ALTA, DAO, LINN, MO, NY, SASK, and based on a wide array of morphological WIN. All species were also field-collected characters. Characters indicated within by the authors in 2009. Morphological square brackets ([ ]) are absent in characters from vegetative (rhizome, the species of SK but are used in bulb, leaf, and scape) and reproductive the description of Allium in floras and (perianth, stamen, pistil, fruit, and seed) monographs throughout the world. structures were measured in a minimum of 30 and 20 specimens, respectively. Allium /_., Sp. PI. 1: 294 (1753). Parts from the middle third of the second Description: Herbs perennial, bulbiferous. 68 (3) September 2010 147 148 C/2 H © I CZ) eft o - ft* ca g ft* 33 E[ y 5 > 'ik t; Go t ^lc Map " * data 02009 l!« f t Figure 1. Geographic distribution of Allium species in Saskatchewan (WB: Water body; MC: Mountain Cordillera; HP: Hudson Plain; PR: Prairie; BP: Boreal Plain; BS: Boreal Shield; TS: Taiga Shield). A) A. schoenoprasum; B) A. textile; C) A. cernuum; D) A. stellatum. Blue Jay Rhizomes condensed [or elongated], ellipsoid, or cordiform, trigonous [or not]. sometimes obsolete (not rhizomatous), Seeds black, elliptical to circular, flat to erect to horizontal. Bulbs tunicate, solitary circular in cross-section. to clustered, [sometimes with basal bulbils], cylindrical to globose; tunicas In this study, we recognize four Allium membranous, papery, or fibrous, smooth species for SK, namely: A. cernuum, A. to reticulate. Leaves alternate; leaf schoenoprasum, A. stellatum, and A. sheaths [buried] or exposed over ground; textile, which are the same recognized leaf blades linear [or rarely elliptical to by McNeal and Jacobsen (2002) and oval], flat, angular, or terete, with 1 or 2 Harms (2003),1121 except that our rows of vascular bundles, and solid or study excludes A. geyeri. The existing hollow in cross-section, sessile, attenuate, herbarium specimens of A. geyeri var. [or rarely narrowed into pesudo-petiole at geyeri in SK1121 are misidentifications base], acuminate [to rounded] in apex. and correspond to A. textile.26 Therefore, Scapes usually central from bulbs, and even though A. geyeri is listed as [slender or] stiff, erect to recurved at the endangered (END)21 and SI (five or fewer upper parts, terete, angular, [orflattened- occurrences and particularly vulnerable winged], with 1- to 3-circular vascular to extinction) in SK,22 this species should bundles, and solid or hollow in cross- be excluded from the rare list as well as section. Inflorescences terminal, usually from the provincial flora. an umbel, [sometimes replaced totally or partially by bulbils], wholly enclosed Key to the Allium species of by a scarious spathe-like bract before Saskatchewan flowering; umbels fascicled to globose; I.Leaf blades terete, hollow in cross- pedicels terete [or rarely angular], thinner section; scapes hollow in cross-section; [or rarely thicker] than the scapes, equal tepals 10.0-15.0 mm long; ovary ellipsoid, [to distinctly unequal] in length. Flowers with hood-like appendages at base; bisexual [or rarely unisexual], regular, capsules ellipsoid; seeds elliptical, actinomorphic; perianth campanulate angular in cross-section- to stellately spreading, with greenish or -1. A, schoenoprasum reddish mid-vein abaxially; tepals 6, in 2 (Fig. 2, see inside front cover) series, usually unequal, connate at base, persistent after flowering; inner ones 1. Leaf blades flat, channelled, semiterete, oblong to ovate, acute to obtuse at apex; or V-shaped, solid in cross-section; outer ones oblong to orbicular, acute to scapes solid in cross-section; tepals subrounded at apex; stamens 6; filaments 3.8-8.8 mm long; ovary subglobose, adnate to the lower part of tepals, without appendages or with crest-like exserted or not, connate and usually appendage at apex; capsules cordiform; dilated at base, entire [or toothed at seeds oval to broadly oval, semiterete in margin]; anthers 2-locular, longitudinally cross-section. dehiscent, usually elliptical, yellowish [or reddish]; ovary superior, greenish, 2. Rhizomes obsolete, erect, 0.5-2.7 [reddish, or brownish], trigonous [or not], mm long; tunicas of bulbs fibrous, sometimes with crest-like (apical) or hood¬ reticulate; leaves 2-4 (usually 2); like (basal) appendages, locules 3, ovules outer filaments non-exserted; ovary usually 2 per locule, placenta axile; style without appendage at apex; styles non- 1, erect, filiform, exserted or not; stigma exserted; seeds broadly oval; flowering conically smooth, [capitate, or rarely trifid].