John C. Semple

Cytotaxonomy and cytogeography of the goldenaster genus Heterotheca (Asteraceae: Astereae)This paper is one of a selection of papers published in the Special Issue on Systematics Research.

Between 1948 and 2008, 668 chromosome number determinations have been reported for individuals of the goldenaster genus Heterotheca Cass. (Asteraceae: Astereae) from Canada, Mexico, and the United States, including 285 newly reported here. This common group of mostly western North American herbaceous annuals and perennials is subdivided into three sections, the most complex of which is section Phyllotheca. Differences of opinion about the taxonomy of the goldenasters, numerous synonyms, and the lack of a comprehensive treatment of the polymorphic villosa complex and other species complexes in section Phyllotheca made it difficult to organize the data into a meaningful discussion of the cytotaxonomy and cytogeography of this genus. Here I present the geographic distribution of all published counts and cytogeography maps of all species of Heterotheca, assigning taxa following recent taxonomic revisions. The sample sizes for species sampled ranged from 1 to 228 reports. All species have a base number of x = ...

The biology of Canadian weeds. 113. Symphyotrichum lanceolatum (Willd.) Nesom [Aster lanceolatus Willd.] and S. lateriflorum (L.) Löve & Löve [Aster lateriflorus (L.) Britt.]

Symphyotrichum lanceolatum, the tall white aster, is a morphologically variable, native North American, polyploid (tetraploid, pentaploid, hexaploid, heptaploid, and octoploid cytotypes) species with a transcontinental distribution. Commonly found along fence rows, ditches, road and rail right-of-ways, and field, pond, and wood lot margins, the species is not a serious agricultural weed but may become problematic in neglected fields, poorly managed pastures, and cultivated fields on recently plowed land. For this review of the biology of the species, we recognize two subspecies, the eastern subsp. lanceolatum and western subsp. hesperium. The former is further divided into varieties lanceolatum, hirsuticaule, interior, and latifolium. Symphyotrichum lateriflorum, the one-sided aster, is also morphologically variable. The distribution of this native, polyploid (diploid, tetraploid, hexaploid, and octoploid cytotypes) extends from the Magdalen Islands and Prince Edward Island in the north, south to Florida,...

The genusAntennaria (Asteraceae: Inuleae) in western North America: Morphometric analysis ofAntennaria alborosea, A. corymbosa, A. marginata, A. microphylla, A. parvifolia, A. rosea, andA. umbrinella

Multivariate analysis of vegetative and reproductive characters was used to examine morphological relatedness amongAntennaria alboroseaA. E. Porsild,A. corymbosaE. Nels.,A. marginataGreene,A. microphyllaRydb.,A. parvifoliaNutt.,A. roseaGreene, andA. umbrinellaRydb. Both pistillate and staminate plants were examined. Some of the characters examined were variable in one species, but stable in another (i.e., presence or absence of papillae on the achenes). Our analyses indicate that the seven species are morphologically distinct. It is hypothesized that theA. rosea agamic complex arose through hybridization amongA. corymbosa, A. microphylla, A. umbrinella, and possiblyA. dioica (L.)Gaertn. However, hybridization between the three former species and others, as well as their subsequent morphological responses to different environmental conditions causes confusion in recognizing the taxa.Antennaria angustifoliaRydb.,A. aridaE. Nels.,A. confinisGreene,A. scariosaE. Nels.,A. foliacea humilisRydb.,A. concinnaE. Nels., andA. viscidulaE. Nels. are considered to represent F 1 hybrids.

Chromosome number determinations in fam. Compositae, tribe Astereae. VIII. Eastern North American taxa. II

Abstract Chromosome numbers are reported for the first time for 245 individuals of 93 taxa and cultivars and two hybrids from 13 genera from eastern Canada and the eastern United States. Nearly all of the reports are for asters in Symphyotrichum plus Doellingeria, Eurybia, Oclemena, and Sericocarpus, and for goldenrods in Solidago and Euthamia. Corrections or changes in identifications for eight previous reports are also listed. The following are first documented reports for the taxa: Chrysopsis highlandsensis, 2n  =  5II from Florida; Solidago simulans, 2n  =  36 from North Carolina; Solidago villosicarpa, 2n  =  18 from North Carolina; Symphyotrichum fontinale, 2n  =  50 from Florida; Symphyotrichum grandiflorum, 2n  =  30 from North Carolina; Symphyotrichum parviceps, 2n  =  48 from Missouri; and Symphyotrichum rhiannon, 2n  =  48 from North Carolina. A number of the counts are first reports for a particular taxon in a state: e.g., Brintonia discoidea, 2n  =  18 from Alabama; Doellingeria umbellata var. umbellata, 2n  =  18 from Tennessee, Eurybia spectabilis, 2n  =  72 from South Carolina; Symphyotrichum oolentangiense, 2n  =  32 from Tennessee.

New names, combinations, and lectotypifications in Heterotheca (Compositae: Astereae)

The following new names and combinations are proposed:Heterotheca barbata (Rydb.) Semple,H. horrida subsp.cinerascens (S. F. Blake) Semple,H. fulcrata vararizonica Semple,H. fulcrata var.senilis (Wooton & Standley) Semple,H. oregona var.compacta (Keck) Semple,H. oregona var.rudis (Greene) Semple,H. oregona var.scaberrima (A. Gray) Semple,H. pumila (Greene) Semple,H. villosa var.pedunculata (Greene) V. Harms ex Semple, andH. zionensis Semple. The following chromosome numbers are reported for the first time:H. fulcrata var.arizonica, 2n=9II;H. horrida subsp.cinerascens, 2n=18II;H. pumila, 2n=9II,2n=18II;H. zionensis, 2n=9II.

A Multivariate Morphometric Analysis of the Solidago chilensis Group in South America and Related Taxa in North America (Asteraceae, Astereae)1

Abstract A multivariate morphometric study of Solidago L. in South America was undertaken to assess the numbers and ranks of taxa that could be usefully recognized. The results of stepwise discriminant, classificatory, and canonical analyses on a matrix of 50 traits of 160 specimens indicated the distinctiveness of the S. chilensis group of taxa from three morphologically similar North American species of the large Solidago subsect. Triplinerviae (Torr. & A. Gray) G. L. Nesom: S. juliae G. L. Nesom, S. leavenworthii Torr. & A. Gray, and S. tortifolia Elliott. Within the South American complex two species with predominantly allopatric distributions were statistically supported: S. chilensis Meyen and S. microglossa DC. were distinguished a priori on stem hair length. The cytogeography of the two species was investigated and all samples were diploid, 2n = 18; S. chilensis (20 individuals from Argentina and one from Chile) and S. microglossa (six individuals from Argentina). Also, two other species of Solidago in South America that are not members of subsection Triplinerivae were found to have been misidentified as members of the S. chilensis complex; European S. virgaurea L. is a member of Solidago subsect. Solidago and native S. argentinensis Lopez Laphitz & Semple is a member of Solidago subsect. Junceae (Rydb.) G. L. Nesom. The name S. chilensis is neotypified.

The biology of Canadian weeds. 114. Symphyotrichum pilosum (Willd.) Nesom (Aster pilosus Willd.)

Symphyotrichum pilosum (Willd.) Nesom, the white heath aster, is a robust, native North American, polyploid, herbaceous perennial. Until recently the species was treated as part of Aster. Its placement in the segregate genus Symphyotrichum follows the revised generic combinations proposed for North American asters. Occurring throughout eastern North America from Nova Scotia and Maine in the northeast, southward to Georgia, west ward through southern Quebec and Ontario to Wisconsin, Iowa, Kansas, and Arkansas in disturbed areas such as fallow land, roadsides, dumps, quarries, arable fields, railroad beds, and embankments, the species is troublesome in the United States but a weed of minor importance in Canada. Two varieties, var. pilosum and var. pringlei are recognized. The former, the hairy variety, is weedier than the latter, the hairless variety. The species commonly occurs in fields following the first year of abandonment and may dominate in the second, or subsequent years. Control may be achieved thr...

Neotypification of Amellus villosus, the identity of a Bradbury collection, and typification of some other goldenasters (Compositae : Astereae)

Nomenclatural problems involving closely related North American goldenasters are resolved. No original type material (a collection by John Bradbury) is known forAmellus villosus Pursh, which is the basionym for the taxon referred to asChrysopsis villosa and more recently asHeterotheca villosa. The species is the first-described taxon inHeterotheca sect.Phyllotheca. A collection by Bradbury (LIV) was found to belong inH. camporum and does not match Purshs protologue. A neotype (PH) was selected from collections by Thomas Nuttall. A problem in the typification of the second oldest taxon in sect.Phyllotheca was encountered. The specimen filed at K as the type ofDiplopappus hispidus Hook. was not the specimen cited in the protologue. A lectotype has been designated from collections by Richardson at BM. Other taxa placed in synonymy are also typified.

Aster breweri: A New Combination for a Rayless Aster Based on Chrysopsis breweri (Compositae: Astereae)

Aster breweri is a rayless, high montane Californian species first described as Chrysopsis breweri and placed in C. subg. Ammodia (=Heterotheca sect. Ammodia). It has always been considered to be related to the goldenaster Heterotheca oregona (synonym: C. oregona) because both lack the well developed short outer pappus whorl and yellow rays typical for Heterotheca. However, Aster breweri has the diagnostic hair and phyllary traits of Aster sect. Eucephalus, not those of Heterotheca. Critical are its smooth-surfaced woolly hairs, lacking the tuberculae typical of Heterotheca. Chrysopsis breweri var. multibracteata is placed in synonymy under Aster brickellioides (including A. siskiyouensis). New combination: Aster breweri. Brewers aster (basionym: Chrysopsis breweri A. Gray (1866); synonym: Heterotheca breweri (A. Gray) Shinners (1951)) was found to be unlike the true goldenasters (Compositae: Astereae) of the genus Heterotheca in that it lacked knobs on the osteolate cells of the uniseriate hairs (Sem-

Heterotheca sect. Ammodia (Compositae: Astereae): A Multivariate Study of H. oregona and Specimens of Brewer's (Golden)aster

A study of the morphological variation among herbarium specimens of Heterotheca sect. Ammodia yielded 1) data supporting the division H. oregona into four previously described varieties, and 2) the exclusion of Brewers (golden)aster from the section and the genus. The types of Chrysopsis breweri var. multibracteata and C. gracilis were determined to be forms of Aster brickellioides and both have been assigned to Aster sect. Eucephalus. The four varieties of H. oregona were found to be distinguishable on the basis of sets of habit, leaf, and pubescence traits. Variety oregona is native to the Cascade and Coastal ranges from Washington to central California. Variety rudis occurs from extreme southern Oregon to east of Monterey, California. The range of var. compacta is similar, but does not extend into the South Coastal Range or Oregon. Variety scaberrima is found in the South Coastal Range. Putative hybrids between pairs of the four varieties have been collected occasionally where sympatric. The following are first reports of chromosome numbers: H. oregona var. oregona, 2n = 9II; H. oregona var. rudis, 2n = 9II; H. oregona var. scaberrima, 2n = 9II. One new combirnation is proposed: Heterotheca brandegei.