USGS Science⌕ Search

Geology topics

Colette C. Jacono

Publications and source records attributed to Colette C. Jacono.

3 recordsLinked to original sources
USGS2006

Water-clover ferns, Marsilea, in the Southeastern United States

A surge in the collection of exotic Marsilea , M. mutica , M. minuta and M. hirsuta in the southeastern United States has prompted the need for updated identification aids. This study provides an annotated key to all water-clover ferns occurring in the region. It describes and illustrates recently documented exotic species and a previously misidentified western introduction. It details the rediscovery of M. ancylopoda , presumed extinct, and confirms its identification as the western species M. oligospora . Finally it clarifies the status and distribution of two additional western North American species introduced to the southeast, M. vestita and M. macropoda .

Castanea↗
USGS2003

A gentic survey of Salvinia minima in the southern United States

The genetic relationships among 68 samples of Salvinia minima (Salviniaceae) were investigated using RAPD analysis. Neighbor joining, principle components, and AMOVA analyses were used to detect differences among geographically referenced samples within and outside of Florida. Genetic distances (Nei and Li) range up to 0.48, although most are under 0.30, still relatively high levels for an introduced, clonally reproducing plant. Despite the diversity AMOVA analysis yielded no indication that the Florida plants, as a group, were significantly different from the plants sampled elsewhere in its adventive, North American range. A single, genetically dissimilar population probably exists in the recent (1998) horticultural introduction to Mississippi. When the samples were grouped into 10 regional (but artificial) units and analyzed using AMOVA the between region variance was only 7.7%. Genetic similarity among these regions may indicate introduction and dispersal from common sources. The reduced aggressiveness of Florida populations (compared to other states) may be due to herbivory. The weevil Cyrtobagous salviniae , a selective feeder, is found in Florida but not other states. The genetic similarity also suggests that there are no obvious genetic obstacles to the establishment or efficacy of C. salviniae as a biological control agent on S. minima outside of Florida.

Aquatic Botany↗