David J. Rosen

• Doctor of Philosophy
• Instructor at Lee College

Great progress in cytotaxonomic research during the last decades indicated an importance of relationships between morphological features, geographical distribution of plants, and chromosome counts. This study is aimed to fill the gaps in our knowledge on Bolboschoenus chromosome numbers related to morphological differentiation of plants and their d...

Rediscovery of the Texas endemic Chloris texensis in Brazoria County, and new records for Ft. Bend, Matagorda, and Waller counties are documented. Collection records outside the narrow Upper Coastal Prairie distribution are also reviewed.

Bothriochloa glabra (Roxb.) A. Camus is reported for Texas. A key is provided to separate B. glabra from B. bladhii (Retz.) S.T. Blake.

This is the first record of Eleocharis mutata in Florida, and the second record in the continental USA, suggesting a potential natural range expansion of this species from the Caribbean region. A key to species of Eleocharis subg. Limnochloa in Florida is included, along with a site description of the occurrence, visual aids for identification, and...

The Follets Island Conservation Initiative is a 179 ha parcel on Follets Island in Brazoria County, Texas. Field work from May 2013 through May 2015 produced a checklist of 130 species of vascular plants representing 41 families and 105 genera from a flora that is 98% native (species) and a protected refuge for fourteen species of conservation inte...

Rosen, D.J. and C. Reid. 2015. Eleocharis ×inaequilatera (Cyperaceae), a new hybrid spikerush from the coastal plain of ABSTRACT Eleocharis ×inaequilatera D.J. Rosen & C. Reid, nothosp. nov., a new sterile hybrid spikerush, is described from the coastal plain of Louisiana and Texas. The hybrid is hypothesized to result from crossing of E. cellulosa...

Introduced accidentally from South America, deeproot sedge is rapidly expanding in a variety of habitats throughout the southeastern United States. Of particular concern is its rapid expansion, naturalization, and formation of monocultures in Texas coastal prairie, one of the most imperiled temperate ecoregions in North America. The objective of th...

Native to temperate South America, deeproot sedge has naturalized throughout the southeastern United States. Often forming dense, homogenous stands, deeproot sedge has become widespread, invasive, and potentially harmful ecologically throughout the coastal prairie ecoregion of Texas. Possessing characteristics (rapid growth, generalized habitat req...

Galveston Island State Park is located near the center of Galveston Island in Galveston County, Texas, U.S.A. The 789.1 ha park lies within the Western Gulf Coastal Plain ecoregion. A floristic survey was conducted from July 2011 through November 2013, and vouchered specimens at TEX collected in the early 70s by R.J. Fleetwood verified, with the go...

Nash Prairie is a 120 ha remnant of Texas upper coastal prairie with a previously reported native vascular plant flora of 289 species. Miscellaneous collections made over the past seven years are reported here, increasing the known native flora to 301 species. resumen Nash Prairie es un resto de 120 ha de la pradera costera superior de Texas con un...

Saline lakes and freshwater playas form the principal surface hydrological feature of the High Plains of the Southern Great Plains. Saline lakes number less than 50 and historically functioned as discharge wetlands with relatively consistent water availability due to the presence of one or more springs. Currently, less than ten saline lakes contain...

Three new species of Eleocharis are described from southern Brazil. Eleocharis pauciglumis is a member of Eleocharis subg. Limnochloa and is similar to E. acutangula. Eleocharis atrobrunnea and E. parvispicula belong to Eleocharis subg. Eleocharis sect. Eleogenus and are similar to Eleocharis flavescens and E. sellowiana. Morphological descriptions...

Cyperus entrerianus (Boeckler) (deeprooted sedge, deeproot sedge, woodrush flatsedge) has become naturalized throughout the Texas coastal prairie ecoregion and is now found throughout much of the southeastern United States. Originally from Argentina, its successful naturalization is linked to its rapid growth, morphological plasticity, and generali...

Paleocharis nearctica gen. & sp. nov (Cyperaceae) is described from a Late Cretaceous achene preserved in Canadian amber. Paleodians is characterized by a narrowly oblong, slightly falcate lenticular achene with a cuneate base and truncate apex, a weak constriction between the lanceolate - obclavate stylopodium that is only slightly set off from th...

Eleocharis cryptica (Cyperaceae), known from pine-oak forest in Durango, Mexico, is described and illustrated. It belongs to Eleocharis subg. Eleocharis ser. Tenuissimae and can be distinguished by its diminutive size, with culms 2–13mm long (including spikelets 1.3–1.7mm long), and the folliform prolongations of its upper sheaths. It is the smalle...

A survey of the vascular flora of Mowotony Prairie, a 42 ha Texas coastal grassland remnant, resulted in a checklist of 199 species of vascular plants representing 41 families and 129 genera. The four families with the most species were Poaceae (45), Asteraceae (38), Cyperaceae (30), and Fabaceae (19). Species-rich genera included Carex (7 spp.), C...

Se describen dos nuevas especies tropicales de Eleocharis subgen. Limnochloa (P. Beauv. ex T. Lestib.) Torr. (Cyperaceae) y se discuten sus relaciones con especies presumiblemente relacionadas. Eleocharis hooperiana D. J. Rosen, de Sierra Leona en Africa tropical occidental, difiere de E. nupeensis Hutch., una especie morfológicamente similar y pre...

Eleocharis gonzaleziae D. J. Rosen, una nueva especie del Altiplano del México norteño, se describe del estado de Durango y se ilustra. Las notas taxonómicas sobre la nueva especie se proporcionan, incluyendo una comparación a una especie morfológicamente parecida, E. bolanderi A. Gray.

Fuirena repens was known for many years only from the Mexican state of San Luis Potosí, where it is documented by a few historical specimens. Recent field and herbarium studies have revealed two additional stations for this species in the states of Queretaro and most recently, Durango. We present a key to Mexican species of Fuirena and an updated d...

Fuirena repens se conoció por más de un siglo únicamente de San Luis Potosí, documentada de unos pocos ejemplares históricos. En este trabajo se revelan dos localidades adicionales de la planta para los estados de Querétaro y de Durango; se presenta una clave para las especies mexicanas de Fuirena y una descripción de F. repens basada en la informa...

A taxonomic synopsis and review of nomenclature is provided for Eleocharis cellulosa, E. mutata, and E. spiralis, three closely related species belonging to subgenus Limnochloa. One heterotypic synonym of E. mutata and the basionym and a heterotypic synonym of E. spiralis are lectotypified. The taxonomic treatment includes a key, detailed descripti...

The Columbia Bottomlands, a Southern floodplain forest formation on the upper Texas coast, historically covered over 283,000 ha but has since been reduced to 25% of its former extent. The importance of this regional ecosystem as critical stopover and staging habitat for Nearctic-Neotropical migratory landbirds gave rise to the Columbia Bottomlands...

A taxonomic study of Eleocharis acutangula (Roxb.) Schult, was conducted in order to better define this poorly understood and variable pantropical species. Multivariate statistical analysis, and ecological and distributional data of worldwide collections of E. acutangula provided the basis for its segregation into E. acutangula subsp. acutangula, E...

The following taxa are documented as new to Texas: Cosmos bipinnatus, Sphagneticola triloba, Lepidium campestre, Lechea minor, Zephyranthes grandiflora, Pavonia hastata, Orobanche minor, and Valerianella locusta, which is also reported new to Arkansas. Significant new collection records are provided for Alternanthera sessilis, Ambrosia bidentata, C...

Dr. Manuel Barros described Eleocharis kleinii in 1966 based on only one collection from Santa Catarina state, Brazil. The species is closely related to E. liesneri differing in features of the culms, floral scales, perianth bristles, and achene surface sculpturing. An expanded description, notes on ecology and conservation status, additional and r...

Systematic study of several species complexes inEleocharis subgen.Limnochloa resulted in the discovery of a new South American species,E. steinbachii. This new species is closely related toE. acutangula, differing in features of the perianth bristles, achene, tubercle, and narrow neotropical distribution. A description and illustration of the new s...

Se describe e ilustra Eleocharis reznicekii (Cyperaceae, subg. Eleocharis, serie Eleocharis), especie con características morfológicas intermedias entre las de Eleocharis densa y las de dos especies de la subserie Eleocharis (E. macrostachya y E. palustris). Se distingue por tener tallos conspicuamente comprimidos (3-5 veces más anchos que gruesos...

Recent noteworthy collections of Cyperus drummondii from the Texas Gulf Prairies and Marshes, Piney Woods Natural Regions, and a first record from Mexico are reported.

An intensive survey of the vascular flora of Nash Prairie, a ca. 120 ha Coastal Prairie remnant in Brazoria County, Texas, resulted in a checklist of 311 species of vascular plants representing 63 families and 197 genera. The seven families containing the most species are Poaceae (70), Cyperaceae (37), Asteraceae (46), Fabaceae (17), Euphorbiaceae...

Field and herbarium studies show Thalictrum texanum, a species of conservation concern, to be distinct from both T. arkansanum and T. debile. The species, which is endemic to southeast Texas, is documented to occur in eight counties. A description of the species, list of exsiccatae, distribution map, discussion of its abundance and environment, and...

Eleocharis reznicekii (Cyperaceae, subg. Eleocharis, series Eleocharis), is described and illustrated. It is morphologically intermediate between E. densa and two species of Eleocharis subseries Eleocharis (E. macrostachya and E. palustris). The new species differs in a combination of characters including conspicuously compressed culms (3 to over 5...

Eleocharis liesneri is reported here for the first time from Brazil and Colombia. These newly discovered specimens represent the only collections known besides the type of the species, and suggest that this taxon might have a peri-Amazonian distribution. A detailed description, key, and illustration to aid in separation of E. liesneri from other So...

Cyperus entrerianus, a native of temperate South America, has become a tenacious weed in the southeastern United States. Herbarium and field studies revealed records of C. entrerianus from an additional 39 counties in the southeastern United States, increasing the number of counties where it is known by 118%. Vegetation sampling at two southeast Te...

New geographic records ofEleocharis obtusetrigona from the Galapagos islands, Guatemala, and El Salvador are reported. A description and illustration ofE. obtusetrigona are provided, along with a key to separate it from other Central and South American species ofEleocharis subg.Limnochloa with which it has been frequently confused.

Gibasis pellucida (Commelinaceae) is reported as a new naturalized weed in Texas. A description of the species and key to Texas genera of Commelinaceae are provided.

A floristic survey of the Dance Bayou Unit, a 263 ha Columbia Bottomland forest stand within the San Bernard National Wildlife Refuge, was conducted in order to provide a checklist of the vascular flora of an old-growth Columbia Bottomland Forest remnant. Collecting trips were made to the refuge unit from November 2001 through September 2004, and r...

Eleocharis mutata (L.) Roem. & Schult, is reported new to the flora of North America north of México based on recent collections from Brazoria Co., Texas, U.S.A. A key to separate E. mutata from other species of Eleocharis subg. Limnochloa in North America north of México as well as a technical description and ecological notes are provided.

Recent collections of Cyperus drummondii Torr. & Hook. from Texas coastal prairies known as "Nash Prairie" and "Bailey's Prairie" are reported along with ecological notes and a synopsis of its Texas distribution.

Andropogon glomeratus (Walt.) B.S.P. var. glaucopsis (Elliott) Mohr is reported for Louisiana. A key to separate the Louisiana taxa in the A. virginicus complex is provided.

Big Branch Marsh National Wildlife Refuge is a U.S. Department of the Interior Fish and Wildlife Service complex comprising approximately 5,870 ha (14,500 acres). A floristic survey was conducted to provide refuge staff with a checklist of vascular plant species, along with species abundance and habitat preference when one existed. Collecting trips...

Phyllostachys bambusoides, native of China, is reported from the floodplain of Thompson Creek, West Feliciana Parish, Louisiana. A key to Louisiana Phyllostachys and a description of the genus and species are included.

ABSTRACT Euthamia carolinianais reported as new to Texas, while Rhynchospora chapmaniiis reported as new to Texas and the West Gulf Coastal Plain. Phytologia 91(1):69-72 (April, 2009). KEY WORDS: Asteraceae, Cyperaceae, Euthamia, Rhynchospora, Louisiana, Texas, West Gulf Coastal Plain. , The following species are reported as new to Texas. Euthamia...