Exhibit F Phytologia
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EXHIBIT F PHYTOLOGIA An international journal to expedite plant systematic, phytogeographical and ecological publication Vol. 77 September 1994 No. 3 CONTENTS , NESOM, G.L., Review of the taxonomy of Aster sensu lato (Asteraceae: Astereae), emphasizing the New World species 141 / NESOM, G.L., Hybridization in the tribe Astereae 298 Phytologia Memoirs available 308 i«BRARV 4 W5. FEB \ NEW tORK BOTANICAL GARDEN Published by Michael J. Warnock 185 Westrldge Drive Huntsville, Texas 77340 U.S.A. PHYTOLOGIA Is printed on acid free paper. PHYTOLOGIA An international journal to expedite plant systematic, phytogeographical and ecological publication Vol. 77 September 1994 No. 3 CONTENTS ^ NESOM, G.L., Review of the taxonomy of Aster sensu lato (Asteraceae: Astereae), emphasizing the New World species 141 ^ NESOM, G.L., Hybridization in the tribe Astereae 298 Phytologia Memoirs available 308 l.RRARV '"5 fEB ) « Published by Michael J. Warnock 185 Westridge Drive Huntsville, Texas 77340 U.S.A. PHYTOLOGIA is printed on acid free paper. PHYTOLOGIA (ISSN 00319430) is published monthly with two volumes per year by Michael J. Warnock, 185 Westridge Drive, Huntsville, TX 77340. Second Class postage paid at Huntsville, TX. Copyright 1994 by PHYTOLOGIA. Annual domestic individual '''"^'^' ^'^^•^^- S'nn^^''" ^ -^^""^^ domestic institutional subscription (12 issues): 5.44.00. Foreign and/or airmail postage extra. Single copy sales: Current issue and back issues volume 72 to present, $400; Back issues (previous to volume 72), $3 00 (add $ 75 per copy postage and handling US [$1 .50 per copy foreign]). Back issue sales by volume: $17.00 per volume 42-71 (not all available as complete volumes); $21.00 per volume 72- present; add per $3^00 volume postage US ($6.00 per volume foreign). POSTMASTER-' bend address changes to Phytologia, 185 Westridge Drive, Huntsville, TX 77340 -8916 Phytologia (September 1994) 77(3): 141-297. REVIEW OF THE TAXONOMY OF ASTER SENSU LATO (ASTERACEAE: ASTEREAE), EMPHASIZING THE NEW WORLD SPECIES Guy L. Nesom Depaitment of Botany, University of Texas, Austin, Texas 78713 U.S.A. ABSTRACT The genus Aster (as tjrpilied by A. amellus L.) and its closest rel- atives comprise the subtribe Asterinae a. 3tr. These ca. 306 species in thirteen genera are primarily restricted to the Old World; Aater is the largest of these (with ca. 180 species) and is restricted to the Northern Hemisphere of the Old World, except for the seventeen species of Aater sect. Calimeridei (the A. harveyanus Kuntze group), which occurs in southeastern Africa, and A. alpinus L., which occurs in Asia and North America. The status of problematic, potentially generic-level Asian groups presently maintained within Aster s. str. is discussed. Boltonia is the only American genus hypothesized to be in the Asterinae. The New World species previously classified primarily within Aster are here ap- portioned among eleven previously described genera and two new ones, including the following (with number of species indicated): Almutaster (1), Ampelaster gen. nov. (1), Chloracantha (1), Canadanthus gen. nov. (1), Doellingeria (11 - three from North America, eight from Asia), Bucephalus (11), Eurybia (28), lonactis (5), Oclemena (3), Oreostemma (3), Psilactis (6), Sericocarpus (5), and Symphyotrichunu, including Vir- gulus (97). The status of Tonestus (eight species) within the Asterinae is considered, but it probably is best placed within the Solidagininae. A taxonbmic account is provided for infrageneric categories and all 181 species of these fourteen American genera (including Tonestus), with new combinations necessary to establish a complete nomenclature; mor- phological summaries are provided for all. The validity and typilication of the name Eurybia (Cass.) S.F. Gray is discussed in detail. Asian Asterinae are generally characterized by obovate, flattened, 2-nerved achenes commonly with glandular faces and are hypothesized to com- prise a monophyletic group. American species (the Symphyotrichinae) are generally characterized by their cylindric to fusiform, terete, multi- nerved, and eglandular achenes, but transitions to flattened and few- nerved achenes apparently have occurred in parallel with Asian taxa. 141 142 P HYTO LO GIA volume 77(3):141-297 September 1994 Similarities between the two groups and the apptu'ent basal position of the American taxa suggest that aU should be included within a single subtribe, the Asterinae. Phylogenetic hypotheses are presented for re- lationships among the American genera. A discussion of chromosome evolution within the tribe Astereae is provided, with reference to the definition of Asterinaean genera. KEY WORDS: Aster, Asterinae, Astereae, Asteraceae, Old World, New World INTRODUCTION Most systematists dealing with the genus Aster have recognized it as tax- onomically difHcult with regard to the delimitation of species as well as the recognition of natural groupings of species. There have been numerous pub- lished studies in the last fifteen years at both levels of the taxonomy of Aster. Two such studies, concentrating on the North American taxa, have provided independent and divergent overviews of the taxonomic structure of the genus (Jones 1980a; Semple & Brouillet 1980a). These botanists, and others, have also provided a great deal of new and critical data on chromosome numbers (see summary by Semple 1992) and morphology within the Aster alliance, clar- ifying the boundaries of species and species groups. The present study reviews recent developments in the taxonomy of Aster s. lat. aad provides a signifi- cantly different perspective on the taxonomy of the group, based primarily on a morphological survey. The taxonomic status of New World and Old World groups is considered; alternative treatments are propose*! for a number of the New World species and suggestions are made for alternative treatments of Old World species and species groups. The comments of Cronquist (1947, p. 147-148) can serve as a starting point in the present review: "Until the publication of the first part of the second volume of the Genera Plantarum [Bentham and Hooker 1873), it was cus- tomary at least in America to regard the various /later- segregates as valid genera. Asa Gray rather reluctantly followed Bentham 's sweeping reduction of most of the segregates, and further pointed out that if these were to be reduced, Brachyactis would have to foUow." "While the extended definition of Aster has certainly not been uniformly accepted, it has been followed by the majority of Amer- ican taxonomists since Gray's adoption of it, more especially so since the swing away from the splitting vogue of the first quarter Nesom: Review of Aster taxonomy 143 of this century. The Benthamian definition, with Gray's addition of Brachyactis, was also adopted by Hoffmann [1890] in his treatment of Compositae for the Naturltchen Pflanzenfamilien.^^ "Although I do not wish to become involved at this time in a discussion of the propriety of the extended definition of Aster, I must support it, with some misgivings, at least until a thorough study of the old-world as well as the American species provides a reasonable basis on which all species can be referred either to Aster proper or to a morphologically definable segregate." The direction of the present review is based on two broad observations, derived in part from a study of the entire tribe Astereae (Nesom 1994e). First, typicaJ Aster a.B.d its closest relatives (the subtribe Asterinae 5. str., comprising fourteen genera) appear to be restricted to the Old World (except for the New World Boltonia). And second, more than half of the species that have been included within New World Aster appear to constitute a diverse but coherent group (the genus Symphyotrichum, as interpreted here), and a smaller number of North American species groups represent separate phylads. Most of the latter have previously been segregated as independent genera, their morphological and phyletic distinctions equivalent to those among other genera in the rest of the tribe. In an earlier study (Nesom 1993c) I placed Sericocarpus as a basal member of the subtribe Solidagininae. In contrast, it is placed here among the North American groups of asters, with the acknowledgment that Cronquist (1947b) was correct in adding this group of species to those that constitute Aster in the broadest sense and that Semple k BrouiUet (1980a) and Jones & Young (1983) correctly placed it near most of its closest relatives in their classifica- tion. Sericocarpus is hypothesized here to be most closely related to the North American genus Eurybia, although its plesiomorphic similarities to the Sol- idagininae may reflect a closeness of common ancestry. Similarly, lonactis was recently hypothesized to be the most primitive member of the Chrysopsidinae (Nesom & Leary 1992), but that subtribe is a well-defined group without lon- actis, which is hypothesized here to be relatively isolated but perhaps most closely related to the genus Bucephalus among North American asters. In the present view, relatively few species of only one other genus, Psilac- tis, need to be added to the other New World species before the entire assem- blage could be considered a single, heterogeneous genus. Species of Psxlactis have been included in Aster, most recently by McVaugh (1984), and Morgan's molecular data (1990, 1993) suggest that species of Psilactts are closely related to others treated here within Symphyotrichum. One species of the genus Tonestus has been included in Aster ( T. kingii [D.C. Eaton] Nesom, see Nesom 1991b). The genus was included among the North American asters in my subtribal classification (Nesom 1994e), and it is 144 P HYT LO GIA volume 77(3):141-297 September 1994 tentatively mjiintained there in the present review. It is anomalous there, how- ever, in its mix of discoid and yellow- and white-rayed species and the papillate collecting appendages of the disc flowers. The other species of Tonestus were mostly treated previously within Haplopappus, which has now been completely dismantled in North America (Nesom & Morgan 1990) and distributed among a number of phylogenetically disparate genera.