Taxonomic studies of North American Sparganium. I. S. hyperboreum and S. minimum

1973 ◽  
Vol 51 (9) ◽  
pp. 1629-1641 ◽  
Author(s):  
Vernon L. Harms
Keyword(s):  
North America ◽  
North American ◽  
Morphological Analysis ◽  
Herbarium Specimens ◽  
Similar Species ◽  
Taxonomic Studies

The taxonomy of the two similar species Sparganium hyperboreum and S. minimum in North America is investigated by a morphological analysis of herbarium specimens and the construction of hybrid indices. It is concluded that despite some hybridization and apparent introgression the two taxa should be recognized as specifically distinct. The criteria for their separation are presented.

Dugesia lugubris (Tricladida: Paludicola), a European Immigrant into North American Fresh Waters

1969 ◽  
Vol 26 (2) ◽  
pp. 221-228 ◽  
Author(s):  
Ian R. Ball
Keyword(s):  
North America ◽  
North American ◽  
Initial Diagnosis ◽  
Similar Species ◽  
Passive Dispersal ◽  
Fresh Waters ◽  
Distribution And Ecology ◽  
Recent Occurrence ◽  
Taxonomic Evaluation ◽  
St Lawrence River

Dugesia lugubris (Schmidt), a Palaearctic freshwater triclad, is described from North America. A morphological and taxonomic evaluation is presented and comparisons with European material and data are made, confirming the initial diagnosis. The known distribution of the species in North America is discussed in relation to what is known of its distribution and ecology in Europe, and it is concluded that the introduction is probably unique and of recent occurrence. It represents the second authenticated case of passive dispersal by man in the freshwater Tricladida, and is almost certainly a result of the shipping plying between the St. Lawrence River and various European ports. The present findings in no way conflict with the opinions of modern American taxonomists that early records of D. lugubris in North America are the results of mis-identification of Cura foremanii (Girard). A key for the separation of these two superficially similar species is provided.

Taxonomic studies on the genus Atrichum in North America

1969 ◽  
Vol 47 (3) ◽  
pp. 353-368 ◽  
Author(s):  
Robert R. Ireland
Keyword(s):  
United States ◽  
North America ◽  
North American ◽  
Distinct Species ◽  
The United States ◽  
Morphological Characters ◽  
Taxonomic Study ◽  
Chromosome Counts ◽  
The Status ◽  
Taxonomic Studies

A taxonomic study was made of several North American taxa in the genus Atrichum. The primary emphasis was on the Canadian taxa and a key to the six species (A. altecristatum, A. angustatum, A. crispum, A. oerstedianum, A. selwynii, A. undulatum) and one variety (A. undulatum var. gracilisetum) of the country is presented. Atrichum oerstedianum, which has been confused with A. undulatum, is added to the moss flora of the United States and Canada. The distribution of A. crispum is clarified and a detailed study of the species revealed new morphological characters that are useful to distinguish it. A variety of A. undulatum, the var. altecristatum, is raised to the rank of a species and morphological and distributional data are given to support the status of A. selwynii as a distinct species. The first chromosome counts are reported for A. selwynii (n = 7) and A. altecristatum (n = 14). Detailed descriptions are provided for A. altecristatum, A. crispum, A. oerstedianum, and A. selwynii.

scholarly journals Molecular systematics of some North American species of Diplostomum (Digenea) based on rDNA-sequence data and comparisons with European congeners

2002 ◽  
Vol 80 (12) ◽  
pp. 2207-2217 ◽  
Author(s):  
Daniel E Galazzo ◽  
Selvadurai Dayanandan ◽  
David J Marcogliese ◽  
J Daniel McLaughlin
Keyword(s):  
North America ◽  
North American ◽  
Sequence Data ◽  
Intestinal Parasites ◽  
Distinct Species ◽  
North American Species ◽  
Similar Species ◽  
The North ◽  
Diplostomum Spathaceum ◽  
Rdna Sequence Data

The systematics of Diplostomum species, common intestinal parasites of piscivorous birds, has long been problematic, owing to phenotypic plasticity and the paucity of morphological features that are often subject to age- and host-induced variation. We sequenced the ITS1–5.8S–ITS2 regions of the rDNA from adult Diplostomum huronense, Diplostomum indistinctum, and Diplostomum baeri obtained from experimentally infected ring-bill gulls (Larus delawarensis) and compared them with partial ITS1 sequences from several species of Diplostomum in GenBank. The three North American species were distinguishable on the basis of ITS sequences. Sequences from D. huronense differed from those of D. indistinctum at 12 sites in ITS1 and 4 sites in ITS2, supporting morphological and morphometric data that indicate the two are distinct species. Sequences of D. huronense and D. indistinctum differed from those of D. baeri at 27 and 24 sites, respectively, in ITS1 and 15 and 12 sites, respectively, in ITS2. Phylogenetic analysis of partial ITS1 sequences revealed that the North American and European species of Diplostomum formed separate groups, with the former being basal to the latter. The results indicated that D. huronense and D. indistinctum from North America are distinct from Diplostomum spathaceum and other similar species from Europe. Furthermore, sequences from specimens identified as D. baeri from North America differed from those of D. baeri from Europe by 3.8% in ITS1 (23 sites). While morphologically similar, the two are not conspecific. Sequences of the North American species have been deposited in GenBank (AY 123042–123044).

Chromosome numbers from pollen in some North American Impatiens (Balsaminaceae)

1974 ◽  
Vol 52 (12) ◽  
pp. 2637-2639 ◽  
Author(s):  
C. C. Chinnappa ◽  
L. S. Gill
Keyword(s):  
North America ◽  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Herbarium Specimens ◽  
Chromosome Counts ◽  
Present Survey ◽  
The One ◽  
Basic Numbers

Chromosome counts for eight species of Impatiens from North American populations have been determined from herbarium specimens. The chromosome number n = 10 for I. ecalcarata Blank, is a new report. It is apparent from the present survey that there are at least three basic numbers (n = 7, 10, and 13) represented in North America as opposed to the one (n = 10) suggested by the earlier workers.

A monograph of Valsa on hardwoods in North America

1985 ◽  
Vol 63 (8) ◽  
pp. 1355-1378 ◽  
Author(s):  
Linda J. Spielman
Keyword(s):  
North America ◽  
North American ◽  
Herbarium Specimens ◽  
Type Specimens ◽  
New Subspecies ◽  
Morphological Studies

The species of Valsa and Cytospora found on hardwoods in North America are reevaluated, based on morphological studies of type specimens, herbarium specimens, and fresh collections. Three sections are accepted in Valsa: sections Valsa, Monostichae Nits., and Cypri Urban, distinguished by the number, size, and arrangement of perithecia, the distribution of ostioles in the disc, and the size of ascospores. Four sections are accepted in Cytospora: sections Cytospora, Torsellia (Fr.) Gvrit., Cytophoma (Hoehn.) Gvrit., and Cytosporopsis (Hoehn.) Gvrit., based on the number and shape of the locules. Correlations between the teleomorphic and anamorphic sections Valsa–Cytospora, Monostichae–Torsellia, and Cypri–Cytophoma are reaffirmed. Six species of Valsa on North American hardwoods are accepted, and two new subspecies are proposed: V. ambiens subsp. ambiens and V. ambiens subsp. leucostomoides (Peck) Spielman. Six species of Cytospora are accepted.

scholarly journals Taxonomic novelties in Cyclodium (Dryopteridaceae) and a key to the species with free veins

2019 ◽  
Vol 152 (3) ◽  
pp. 521-530
Author(s):  
Amabily Bohn ◽  
Fernando B. Matos ◽  
Paulo H. Labiak
Keyword(s):  
New Species ◽  
Morphological Characters ◽  
Herbarium Specimens ◽  
Similar Species ◽  
Conservation Assessment ◽  
Phylogenetic Studies ◽  
Important Region ◽  
Standard Procedures ◽  
Taxonomic Studies ◽  
A New Species

Background – Cyclodium is a neotropical fern genus comprising about ten species. Most species are found in northern South America, and the foothills of the Guiana Shield is an important region for species diversification. Our phylogenetic and taxonomic studies of the genus demonstrated the need to describe a new species and to recognize a variety at species level.Methods – This study is based on herbarium specimens from CAY, HUA, INPA, MBM, NY, P, RB, UC, UFP, UPCB, and US. Morphological characters were analyzed using standard procedures. The indumentum and spores of the new species were studied using a scanning electron microscope. Species delimitation is proposed based on our preliminary phylogenetic studies, as well as on morphology and geographical distribution.Key results – Cyclodium alansmithii Bohn & Labiak is recognized as a new species, described, and illustrated. The most similar species is Cyclodium inerme (Fée) A.R.Sm., from which it differs by ovate-lanceolate and bicolored scales, reduced fronds, truncate pinna bases, and non-ciliate indusia. Cyclodium alansmithii is currently assessed as Endangered (EN) using IUCN criteria, but more fieldwork and herbarium studies are necessary to establish a more accurate conservation assessment. Cyclodium trianae (Mett.) A.R.Sm. var. chocoense A.R.Sm. is here elevated to species rank. A key to species of Cyclodium with free veins is provided.

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