Volume 83 - Issue 2 (Sept 2018)

Werier, David. 2017. Catalogue of the Vascular Plants of New York State. Memoirs of the Torrey Botanical Society, 267: 1–542.

Hardbound. $35.00. ISBN978-0-9996525-0-3. (also available as e-book).

ABSTRACT The netted pawpaw (Annonaceae, Asimina reticulata) is a widespread Florida endemic plant that produces relatively few fruits. To understand its distribution and reproductive success, we posed three questions: (a) how do time-since-fire (TSF) and pollinator visitation influence reproductive success, (b) is it pollinator dependent, and (c) does outcrossing increase reproductive success? In 2016, we studied 157 plants in three flatwoods burn units (last burned, 2015, 2012, or 2001) and one grazed pasture at Archbold Biological Station in south-central Florida. Plants in pasture and recently burned flatwoods exhibited greater flower, fruit, and seed output, suggesting that habitat openness may promote competitive release or increased pollinator visitation. Pollinator visitation was greatest on plants within the 1-yr TSF, and the hairy flower scarab (Trichiotinus viridans) was the most prevalent visitor across all sites. Autogamously crossed flowers produced no fruit, confirming that seed production is pollinator dependent. Although fruit retention (10.0%) and seed germination (27.8%) were low after geitonogamous crossing, close and far outcrossing increased retention (30.8% and 39.6%) and germination success (41.6% and 46.4%). This research suggests that A. reticulata reaches its maximum reproductive potential in open areas after outcrossing events, and that low fruit set may be due to the lack of an effective pollinator, resulting in inbreeding depression. Additionally, an investigation into raccoons (Procyon lotor) as fruit consumers and potential seed dispersers suggests that seeds may benefit from gut scarification.

ABSTRACT The Freedom Hills Forever Wild Tract (FHFWT) is a 13,800 ha property acquired through multiple purchases by Alabama’s Forever Wild Land Trust beginning in 2001. The FHFWT is managed by the Alabama Department of Conservation and Natural Resources for habitat conservation, as a wildlife management area, and for outdoor education. An intensive floristic study of this area was conducted from March 2012 through February 2017. A total of 761 taxa (757 species) from 431 genera and 136 families were collected, with 328 taxa representing county records. A total of 104 nonnative taxa were collected during the surveys. Forty-three percent of the total collections were county records and 72 exotic taxa collected during this survey were determined to be county records. Plant collections were deposited at the Alabama Natural Heritage Section Herbarium (ALNHS) with duplicates distributed to Anniston Museum of Natural History (AMAL), Auburn University Herbarium (AUA), Jacksonville State University Herbarium (JSU), and the University of West Alabama Herbarium (UWAL).

Triadica sebifera (L.) Small (EUPHORBIACEAE)— King and Queen County: Virginia Seasonally inundated Nyssa biflora Walt. swamp in backwater zone of a man-made pond near the York River shoreline, approximately 8 km southeast of the Town of West Point (lat: 37.476529; lon: 76.727332). Eight individual saplings were found growing on hummocks among the following associates: N. biflora, Liquidambar styraciflua L., Morella cerifera (L.) Small, Eubotrys racemosus (L.) Nutt., Ilex opaca Aiton var. opaca, Juncus effusus L., Osmundastrum cinnamomeum (L.) C. Presl var. cinnamomeum, Acer rubrum L., Woodwardia areolata (L.) T. Moore, Dulichium arundinaceum (L.) Britton var. arundinaceum, and Cephalanthus occidentalis L. All specimens were relatively young saplings (estimated at 3–5 years), and all were found within an area circumscribed by an approximate 50 m radius; no flowering or fruiting was observed on the collection date (15 July 2016) or on a subsequent site visit (17 September 2016). 15 July 2016, D.A. DeBerry 892. Voucher specimen deposited at the College of William & Mary Herbarium, Williamsburg, Virginia (WILLI 82064).

Significance. This is the first account of Chinese tallow tree (Triadica sebifera (L.) Small) in Virginia and, to the best of our knowledge, the northernmost record of this species in the Atlantic states1 (University of North Carolina Herbarium [NCU] 2017, USDA, NRCS 2017). Chinese tallow tree was introduced to the USA from China in the late 18th century for the economic potential of the fruits in the soap-making industry (DeWalt et al. 2011). Based on correspondence from the time, it is believed that the original populations of this species were introduced by Ben Franklin via shipments of seeds from London to associates in Georgia in the late 1700s (Bell 1966). Although it was held by some that the ‘‘Franklin trees’’ were the source for the genotype that would eventually become a problematic invader in the Gulf Coast states (see discussion under Invasiveness below), recent work has implicated early-1900s US Department of Agriculture (USDA) introductions in Texas as the invasive genotype (DeWalt et al. 2011). The latter trees were being tested as potential oilseed crops, and the planting program was expanded to other Gulf states in the mid-1900s. The original Franklin trees are relegated to a few thousand square miles in northeast Georgia and adjacent South Carolina. As of summer 2016, the US distribution for all genotypes was understood to include 10 states ranging from North Carolina, south to Florida, and west to central Texas, with disjunct occurrences in northern California (USDA, NRCS 2017).

ABSTRACT Stable isotopic analysis of water use patterns in wetland vegetation can provide insight into the anticipated ecophysiological response of individual species to seasonal and/or episodic changes in water quality such as saltwater incursion into freshwater wetland ecosystems. In this study, variation in water source utilization over the course of a growing season was investigated in Taxodium distichum (baldcypress), a foundational species in both naturally occurring wetlands and regional wetland restoration projects in the southeastern United States. Over the course of the 2014 growing season, water use patterns were monitored in three baldcypress stands at the Timberlake Observatory for Wetland Restoration (TOWeR) in Tyrrell County, North Carolina, by comparing the isotopic composition (d2H and d18O) of xylem water extracted from plant tissue to that of the available water sources: surface water, sediment porewater, groundwater sampled from multiple locations in the region, and rainwater. Results indicate that water sources that are impacted by periodic saltwater incursion may be utilized by baldcypress at TOWeR, but the short-term health and reproductive competency of baldcypress at the site has not been negatively impacted by seasonal, episodic, surface water salinity incursions at the site.

Charmichael et al Supplemental

Poa iconia Azn. var. iconia (POACEAE) – Maryland, Howard County: In wooded back yard, growing in moss, 13 May 1989, E. Cohen 22 (US); Prince George’s County: Near Margaret Brent Dormitory, College Park, Apr 1939, R. Rappleye 1552 (US); Virginia, City of Alexandria: Tarleton Park, ca. 0.25 km WNW of the intersection of S. Gordon Street and Wheeler Avenue; frequent in rich, silty loam of meadowy glade of ancient Piedmont/Central Appalachian Floodplain Swamp (Pin Oak-Swamp White Oak Type): Quercus palustris-Quercus bicolor/Carex tribuloides-Carex radiata-(Carex squarrosa) Forest (USNVC: CEGL006497) remnant along the old channel of Holmes Run, 16 Apr 2018, R.H. Simmons 4359 (AVCH) and 1 May 2018, R.H. Simmons 4363 (AVCH, NY, US, and Virginia Dept. Conservation and Recreation, Division of Natural Heritage herbarium); North Carolina: May 1928, B.W. Wells s.n. (US).

Significance. These are the first reportings of Poa iconia for the eastern United States, and first published record for North America.

ABSTRACT The unique morphology of quillworts has received limited attention, and such studies have been limited to only a few species. Our extensive field work during the past two decades has revealed variation in the structures of the plant, including the rhizomorph, scales, phyllopodia, and abscission caps. Polarity of the axes of southeastern quillwort rhizomorphs varies from discoid (most species), to elongate, to upright with axis branching in several species. In species of intermittent streams, these branched rhizomorphs produce plantlets that break off in running water. Scales are tiny brown or black structures in alternating whorls with sporophylls (leaves). They are often overlooked and easily removed when rinsing specimens. Found in most southeastern terrestrial/amphibious species, scales are absent from aquatic species. Scales are distinct from phyllopodia, the sclerified bases of sporophylls, but intermediates between scales and phyllopodia occur. Not all species with scales have phyllopodia. Although scales cannot be used for determination of species, their presence or absence is of taxonomic value. Research on southeastern Isoetes phylogeny could help determine which of the rhizomorph and scale characters are plesiomorphic.

ABSTRACT The oak mistletoe (Phoradendron leucarpum, Viscaceae) is well-documented to exhibit preference for a few potential host species in a given locality, even when many potential host species are present. In trying to explain this distribution, we examined the mechanisms by which mistletoe seedlings recognize potentially suitable hosts in the Piney Woods ecoregion of east Texas. An initial survey of patterns of infection on the campus of Sam Houston State University revealed that water oak (Quercus nigra) was host to nearly half of the mistletoes observed, despite comprising less than 15% of trees surveyed. Field experiments demonstrated that light, host physiochemistry, and volatiles released from potential host trees serve as cues affecting the viability and establishment of mistletoe seedlings. These results provoked further study in controlled laboratory settings, in which it was demonstrated that chemical compounds in the bark of local host trees (compared to trees that serve as hosts elsewhere, but not in our survey) induce significantly although slightly greater seedling viability. Establishment of haustoria depended only on the presence of these chemicals, regardless of host species. Importantly, we demonstrated that three common monoterpenes, limonene, b-myrcene, and b-phellandrene induce a positive growth response of mistletoe radicles. These results taken together suggest a model to explain local host preference in P. leucarpum, in which covariation between mistletoe fruit maturity and monoterpene production by hosts determines the distribution of successful haustorial establishment.

ABSTRACT A floristic survey was conducted of Crowders Mountain State Park for all vascular species from 2010–15. Crowders Mountain State Park was established in 1974 to protect a geologically unique North Carolina Piedmont site. In addition, it is known for its rare plant species. A total of 420 taxa was collected in this study, representing 418 species in 280 genera from 103 families. This includes 267 previously undocumented species for the park. Nine species are listed as either endangered, rare, of special concern, threatened, or watch-listed for North Carolina.