Biosystematic studies in the North American species of Linum, section Adenolinum (Linaceae)

1971 ◽  
Vol 49 (8) ◽  
pp. 1379-1388 ◽  
Author(s):  
Theodore Mosquin
Keyword(s):  
North American ◽  
Morphological Evolution ◽  
North American Species ◽  
Evolutionary Trends ◽  
Isolated Populations ◽  
Life Habit ◽  
Good Pollen ◽  
The North ◽  
Native North American ◽  
Variation Patterns

Variation patterns and interpopulational relationships were examined in Linum lewisii Pursh and L. pratense (Norton) Small, the two native North American blue-flowered flax species. The two principal evolutionary trends in the North American populations have been toward self-pollination and an annual life habit. A third trend, toward greater outcrossing, is considered probable. Hybridizations between and within species indicate that evolution has occurred mainly by the accumulation of small genic changes in geographically isolated populations. The buildup of sterility barriers between populations regardless of species has not been extensive and in no case do hybrids have less than 30% good pollen. In general, morphological evolution has occurred independently of the buildup of sterility barriers. A new taxonomic combination, L. lewisii ssp. lepagei (Boivin) Mosquin, is adopted.

scholarly journals Molecular Evidence for an Asian Origin and a Unique Westward Migration of Species in the Genus Castanea via Europe to North America

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1006B-1006
Author(s):  
Ping Lang ◽  
Fenny Dane ◽  
Thomas L. Kubisiak ◽  
Hongwen Huang
Keyword(s):  
North America ◽  
North American ◽  
Sequence Data ◽  
Morphological Evolution ◽  
North American Species ◽  
Molecular Evidence ◽  
Westward Expansion ◽  
Dna Sequence Data ◽  
The North ◽  
Sister Clade

The genus Castanea (Fagaceae), which contains three sections and seven species, is widely distributed in the deciduous forests of the Northern Hemisphere. The phylogeny of Castanea was estimated using DNA sequence data from five different regions of the chloroplast genome. Sequencing results support the genus Castanea as a paraphyletic group with C. crenata, the Japanese chestnut, representing an early divergence in the genus. The three Chinese species form a strongly supported sister clade to the North American and European clade. A unique westward expansion of extant Castanea species is hypothesized with Castanea originating in eastern Asia, an initial diversification within Asia during the Eocene, followed by intercontinental dispersion and divergence between the Chinese and European/North American species during the Oligocene and a split between the European and North American species in the early Miocene. The differentiation within North America and China might have occurred in late Miocene or early Pliocence. The North America species are supported as a clade with C. pumila var. ozarkensis, the Ozark chinkapin, as the basal lineage, sister to the group comprising C. pumila var. pumila, the Allegheny chinkapin, and C. dentata, the American chestnut. Morphological evolution of one nut per bur in the genus may have occurred independently on two continents.

The North American Species in Group VII of Ips De Geer (Coleoptera: Scolytidae)

1965 ◽  
Vol 97 (2) ◽  
pp. 193-198 ◽  
Author(s):  
G. R. Hopping
Keyword(s):  
United States ◽  
New Species ◽  
North American ◽  
North American Species ◽  
The North ◽  
Northern United States

AbstractGroup VII of North American Ips contains I. thomasi, new species, I. borealis Swaine and I. swainei R. Hopping. They are less than 4.0 mm. long and females have the front of the head or at least the vertex smooth and shining, impunctate, or with very fine sparse punctures; males are more coarsely granulate-punctate on the frons. The species are described and a key is given. All breed in Picea in Canada and northern United States.

Synopsis of the North American Species of Xylaria and Poronia (Continued)

1887 ◽  
Vol 3 (10) ◽  
pp. 109 ◽  
Author(s):  
J. B. Ellis ◽  
B. M. Everhart
Keyword(s):  
North American ◽  
North American Species ◽  
The North

A SYNOPSIS OF THE NORTH AMERICAN SPECIES OF SYNDIPNUS (HYMEN., ICHNEUMONIDAE)

1940 ◽  
Vol 72 (7) ◽  
pp. 135-145 ◽  
Author(s):  
G. Stuart Walley
Keyword(s):  
United States ◽  
North American ◽  
The United States ◽  
North American Species ◽  
National Museum ◽  
United States National Museum ◽  
The North

As noted below the two North American species described in Syndipnus by workers appear to belong in other genrra. In Europe the gunus is represented by nearly a score of species and has been reviewed in recent years by two writers (1, 2). North American collections contain very few representatives of the genus; after combining the material in the National Collection with that from the United States National Museum, the latter kindly loaned to me by Mr. R. A. Cushman, only thirty-seven specimens are available for study.

scholarly journals THE NORTH AMERICAN SPECIES OF MAMESTRA, Ochs.

1881 ◽  
Vol 13 (6) ◽  
pp. 126-130
Author(s):  
A. R. Grote
Keyword(s):  
North American ◽  
North American Species ◽  
The North

The species of this genus have hairy eyes, unarmed tibiæ and a tufted thorax. The dorsum of the abdomen is more or less tufted, but in some species the tuftings are not noticeable. Several species which seem to me to belong to Graphiphora (Taeniocanpa) have been referred to this genus ; among these I may mention orobia of Harvey, modesta, incincta and thecata of Morrison, and the species described by me as rufula and puerilis.

The North American Allies of Hylobius piceus (De Geer) (Coleoptera: Curculionidae)

1957 ◽  
Vol 89 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Stephen L. Wood
Keyword(s):  
North American ◽  
Distinct Species ◽  
Morphological Characters ◽  
North American Species ◽  
Winged Form ◽  
The North ◽  
The Status ◽  
Field Workers ◽  
Dimorphic Species ◽  
Biological Differences

While investigating the biology of the North American species of Hypomolyx, field workers in Manitoba found a vestigial, or short-winged, and a long-winged form under apparently identical conditions in about equal numbers. Although biological differences were nor then apparent, there was doubt as to whether they were dealing with one dimorphic species or with two distinct species, A search for morphological characters brought to light numerous differences between the two forms, supporting the view that two species were present. These differences, a description the previously unrecognized species, and notes concerning the status of the genera Hylobius and Hypomolyx are reported below.

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