Volume 75 - Issue 4 (Dec 2010)

Isoetes microvela D.F. Brunt. (ISOETACEAE)— Sampson County: along east shore of Black River, 31 August 2006, Brunton and McIntosh 16833 (OAC, MO, Brunton pers. herbarium, LeBlond pers. herbarium).

Significance. These collections document the third known population group of the narrowly endemic Isoetes microvela (Small-veiled Quillwort, Thin-wall Quillwort), so far found only along fresh blackwater streams of the outer coastal plain of southeastern North Carolina. Isoetes microvela is a recently described taxon (Brunton and Britton 1998). Now recognized as a Federal Species of Concern, it is listed as State Endangered by the North Carolina Plant Conservation Program (North Carolina Department of Agriculture and Consumer Services 2009)). It has a global status of Critically Imperiled with a global rank of G1 and state rank of S1 (NatureServe 2009).

Schoenoplectus mucronatus (L.) Palla (CYPERACEAE)—King William County: Virginia Aquatic Resources Trust Fund (TNC) wetland restoration site, approximately 8 km west of Aylett on West River Road (Route 600). Approximately 50 plants were found growing in a seasonally ponded area along the southeast perimeter of the site among the following mixture of species: Persicaria maculosa Gray, Andropogon virginicus L., Rumex crispus L., Eleocharis palustris (L.) Roem. & Schult., Portulaca oleracea L., Digitaria ischaemum (Schreb.) Schreb. ex Muhl., and Bidens aristosa (Michx.) Britton, 14 July 2009, N. McGoff and N. Zinn. Voucher specimen deposited at the Massey Herbarium at Virginia Tech, Blacksburg, Virginia (VPI 105248).

Significance. This is the first account of bog bulrush [Schoenoplectus mucronatus (L.) Palla] in Virginia and, to the best of our knowledge, the first record of this species within the South Atlantic states (Smith 2002, Virginia Botanical Associates 2009, United States Department of Agriculture-Natural Resources Conservation Service [USDA-NRCS] 2009). Bog bulrush is native to Africa and Eurasia and is listed as a problematic weed in 43 countries, presumably owing to its prolific colonization of rice fields and resistance to herbicide treatment (Smith 2002, Washington Noxious Weed Control Board 2010).

ABSTRACT Amaranthus (Amaranthaceae) is a globally distributed plant genus composed of both weedy and cultivated species. While there have been previous attempts to resolve phylogenetic relationships within the genus, little attention has been placed on systematic relationships of the federally threatened coastal species Amaranthus pumilus Raf., endemic to eastern United States barrier islands, nor on genetic variability within the genus. In the present study, single primer ISSRs were employed to measure both genetic diversity and the phylogenetic position of A. pumilus. Leaf tissue samples were taken from wild populations on Fenwick Island, Delaware and from wild and propagated populations on Assateague Island National Seashore, Maryland. Genetic variation was detected among and within A. pumilus populations, though variability was low. Fenwick populations exhibited the highest genetic variability (h 5 0.1016), while on Assateague the wild A. pumilus population had higher variability (0.0340) than the propagated population (0.0185). Due to its desirable characteristics in plant breeding trials, genetic variation within A. pumilus was also compared to variation of grain varieties A. hypochondriacus L. and A. cruentus L. Genetic diversity within A. pumilus was lower than either grain species sampled (0.2263 and 0.2947). Phylogenetic analyses included 41 accessions representing 33 Amaranthus species, and maximum parsimony, neighbor-joining, and Bayesian consensus trees were constructed. Though considerable phylogenetic signal was detected within the data matrix, phylogenetic resolution was low. Amaranthus pumilus grouped with the coastal species A. arenicola I.M. Johnst. in all consensus trees, which is the first postulated relationship of this pair.

Bryson, Charles T. and Michael S. DeFelice (eds.). 2009. Weeds of the South. University of Georgia Press, Athens, Georgia. 468 p. $28.00. Softcover ISBN 978-0-8203-3046-4. Photographs by Arlyn W. Evans.