Associate Professor, Plant Systematics

George Mason University



line decor
line decor




Digital Imaging of the Virginian Specimens in the Ted R. Bradley Herbarium: Summer-Fall 2015

Summer crew: Manuela, me, Maryam, Joey, Ushna, and Sophia. We are sampling civet coffee here. The placement of herbarium specimens in the light-box is guided by raised corner guards.
Joey working on the last folder: Tipularia. Maryam working on the last folder: Tipularia.
Kathryn working on the last folder: Tipularia. Getting to the last sheet...
Done! Fall crew: Kathyrn, me, Joey and Maryam (not pictured: Samantha). Over 35,000 sheets imaged, processed, and made available online at Here's to NSF and Virginia Native Plant Society for supporting this project! And to Kathryn for these great photos.

BIOL345 Plant Ecology: Fall 2015

My class on top of Hawksbill Mtn, Shenandoah National Park - one of multiple field-trips. One press for each student for semester projects. Mounting the final specimens. All told, students found +70 native woody plants species within our suburban campus.

Alberta & British Columbia, Canada search for Melampyrum: August 2015

A surprise was the extensive inland sand deposits - here west of Fort Saskatchewan, Alberta with Jack Pine overstory (Pinus banksiana). Our quarry, Melampyrum lineare, with bearberry host (Arctostaphylos uva-ursi).
Maryam holding excavated blueberry (Vaccinium sp.) host a with whitish haustorial root from M. lineare - visible over her over 4th finger Getting ready to press the specimens. Credit: Maryam Sedaghatpour.
The typical suite of species found with M. lineare: blueberry, bearberry, Rosa acicularis, and service-berry (Amelanchier alnifolia). We sampled +10 individuals per population and made separate DNA vouchers for each. Credit: Maryam Sedaghatpour. Wolf scat from the previous winter filled with undigested fur. Credit: Maryam Sedaghatpour.
Shores of Slave Lake, Alberta. We collected the species on the sandy erosional benches just inland from the beach. A close up of serviceberry fruit and leaves.
Maryam collecting M. lineare from extensive lichen beds. The Fraser River in British Columbia.
Looking towards Jasper National Park. We took a break from collecting to visit this spectacalar place. Roadside elk, Jasper National Park. A view of Angel Glacier.
Castilleja sp. at about 14,000 feet in Jasper National Park. Remarkable old-growth cedars with an Oreopanax understory at an inland temperate rainforest reserve maintained by UBC-Prince George. These forests stood in stark contrast to what we had observed elsewhere on our travels.
An extensive population of M. lineare parasitizing a blueberry shrubland north of Prince George, BC. Our trusty rental Jeep on a ferry crossing nearing Banff National Park at the close of our trip.

Massanutten Mountains search for Melampyrum lineare: July 2015

The southern range of the Massanutten Mountains, Virginia - home to one of the closer populations of M. lineare relative to Mason. At a wooded wetland glade on the way to the site, we encountered dense stands of cinnamon fern (Osmunda cinnamomea), false yellow fox-glove (Aureolaria sp.) and yellow-fringed orchid (Platanthera sp.).
The Massanuttens have extensive exposures of sandstone that create the right edaphic conditions for many acid-loving heath plants, which may host M. lineare. Maryam encounters living M. lineare for the first time! A small individual of M. lineare amongst terrestrial lichen - the species of Vaccinum and Gaultheria in this picture may be its host.
A population of wintergreen, Gaultheria procumbens, in moss. M. lineare (by the right shoulder of Farrah) among multple species of heath plants including, Vaccinium sp., Gaultheria procumbens, Epigaea repens, Kalmia latifolia and Rhododendron sp. Yellow fringed orchid (Platanthera ciliaris).

BIOL344 - Plant Diversity and Evolution: Spring 2015

My BIOL344 class at Turkey Run Park along the Potomac, which always has a great show of spring ephemerals. Dwarf-ginseng (Panax trifolius) amid wild-ginger (Asarum canadense) and Dutchman's-breeches (Dicentra cucullaris) Sessile-leaved Bellwort, Uvularia sessilifolia.
Virginia bluebells (Mertensia virginica) A bit earlier in the year, bloodroot (Sanguinaria canadensis)

Travels to Austin, Texas: March 2015

The Texas Capitol building. Fun fact: the pink granite gives the building a higher than average background level of radiation. Texas bluebonnets, Lupinus texana. I attended a lecture by the Grants and received a signed copy of their recent book.
Indian paint brush (Castilleja sp.) amid bluebonnets. Sophora secundiflora, or what is called mountain laurel by Texans.
Red-bud (Cercis canadensis) Mexican freetail bats emerging from the Congress Street bridge at sunset.

Melampyrum lineare population hunt, US East Coast: Summer 2013

Virginia, Grayson Co. Unknown yellow fungi. Virginia, Roanoke Co. Melampyrum selfie. Connecticut, Kent Co. Red eft.
Virginia, Grayson Co. Broad-leaved specimen. Connecticut, Kent Co. Mountain summit with granitic heath balds. Connecticut, Kent Co.
Maryland, Harford Co. Alluvial sands in Piedmont. Virginia, Stafford Co. Fort A.P. Hill population - Coastal Plain/Piedmont transition.
North Carolina, Hanging Bluff State Park - a mountain island in the Piedmont. North Carolina, Stokes Co., Hanging Bluff State Park.
North Carolina, Surry Co. Blue Ridge Mtns. Virginia, Roanoke Co., Poor Mountain heath balds.

Delmarva Peninsula: Karoline's first Melampyrum lineare collecting trips, June 2013

Melampyrum lineare (Orobanchaceae) is a hemiparasitic wildflower that is ant-dispersed. An individual is visible to the left of the steno pad. Typical habitat of M. lineare (center-right) includes its host plants such as pine, red maple, and mountain laurel.
M. lineare produces ant-attracting compounds in its flowers and fruits. An ant is visible on the flower. Ants are rewarded with the seed's fatty elaiosome, which ants consume after carrying the seed back to their underground nest thereby "planting" it.
Plants tend to grow on sun-warmed, well-drained soil, which ants may prefer. An individual showing the deeply toothed bases of the inflorescence bracts. Several robust individuals showing the highly reduced root system typical of parasitic plants.

Madagascar II : Morgan's Commiphora collecting trip, May-June 2013

Morgan collecting Commiphora in Madagascar. A Commiphora species growing directly out of the limestone karst of Ankarana National Park.
Commiphora laxcymigera. Commiphora sp. A newly discovered Commiphora species with oak-like bark.

Victory Bog, Vermont: November 2010

Victory Basin is a 4970 acre wetland complex in northern VT containing an oligotrophic peatland ("boreal bog"). Black spruce (Picea mariana) in background.

Thick carpets of Sphagnum (peat moss) border the edges of open water.
Plumose achenes of a Clematis species, and the woody catkins of a shubby alder (Alnus sp.) Berries of Smilax herbacea (smooth carrion flower) with dried fronds of Royal Fern (Osmunda regalis).
A broad sedge and ericad wetland. A nice shot of transition from open peatland to shrubs to forest.
Stiff clubmoss (Spinulum annotinum). A beard lichen (Usnea sp.) A pixie-cup lichen (Cladonia sp.)


Chamela Research Station, Jalisco, Mexico: June 2010

On top of the water tower at Chamela Research Station, Pacific Ocean over my left shoulder. The reseach station is part of the largest tract of tropical dry deciduous forest on the Pacific coast of Mexico. The station is barely visible on the left hill.
An epiphytic bromeliad, Bursera instabilis, a Mexican endemic species with lianescent crown.
An epiphytic orchid, Encyclia trachycarpa. Cocholospermum vitifolium flower.
One of several epiphytic orchids Schomburgkia galeottiana, that is also myrmecophilous (ant-hosting). An arborescent cactus (ca. 4 m), Opuntia excelsa. Flower and dehiscing fruit of , Encyclia trachycarpa,note the dust-like yellow seeds.
Small resident ants located at the leaf bases of Schomburgkia galeottiana. One is located on a papery nest, center-right. Female (back) and male (front) individuals of as yet unidentified lizard. Anacardium occidentalis fruit (Cashew), with fleshy yellow pedicel and purple ovary.


Collecting Commiphora in Madagascar: December 2009 to February 2010

This material is based upon work supported by the National Science Foundation under Grant No. 0919179.

Flatida coccinea Baobab Alley, Morondava Chameleon, Anadasibe
Commiphora mafaidoda, Ranobe. Unknown Commiphora sp., Tulear Collecting C. guillaumini, Morondava
C. ankaranensis, Diego Prov. Pseudaril of C. guillamini Seedling of C. orbicularis, note cotyledons.
Dissected fruit of baobabs (L: Adansonia rubrostipa, R: Adansonia za) Canopy of Adansonia rubrostipa, Ranobe.
Commiphora stellulata, Diego Prov. eroded karst of Mt. Francais, Diego Prov.
Limestone hills, Commiphora forest, Tulear. Open ferric sands with C. orbicularis, Belalanda.
Coming back from collecting in Tulear, Central plateau of Madagascar. Oxcarts were common.
Palm (Bismarkia) savanna, Isalo National Park. Montane rainforest, Andasibe National Park.
Indri lemur, Andasibe Adult male Parson's chameleon, Andasibe.


Shenandaoh National Park: BIOL 345 (Plant Ecology) class trip, October 2009

Class photo on summit of Hawksbill Mountain. Top row: Chris, John, Lyana, Garrett. Middle: EJ, Anna, Rosalind, JP, Sean. Bottom: Me View from the summit, looking west.
Hydrangea cinerea (Ashy Hydrangea) at Dark Hollow Falls . Hydrangea cinerea (Ashy Hydrangea) infructescence.

Delmarva Peninsula: Sara's Kosteletzkya pentacarpos collecting trip, August 2009

Kosteletzyka pentacarpos, the Virginia Saltmarsh Mallow. Sara collecting in Delaware. Kristen and Sara pressing specimens.
Sara collecting in Dorchester Co., Maryland near Taylor's Island. Interesting color morphs of K. pentacarpos.
Visiting Jack Gallagher's lab at the University of Delaware. Visiting the experimental field plot of K. pentacarpos at the University of Delaware.


Snowbird, Utah: Botany 2009 Meetings, July 2009

Kristen presented her Master's thesis at the conference. In this photo, we're holding snowballs. Catherine Pass in the Wasatch Mountains, Utah.
Rosy Indian Paintbrush (Castilleja rhexifolia) Leafy Jacob's Ladder (Polemonium foliossimum)
Richardon geranium (Geranium richardsonii). Sticky Indian Paintbrush (C. appllegatei) and Leafy Jacob's Ladder Tolmie owl clover (Orthocarpus tolmei)


Yucatan Peninsula, Mexico: International Biogeography Conference, January 2009

Violaceous Trogon Strangler Fig and Andrea. Strong Billed Woodcreeper


Bursera simaruba fruit . Unidentified bee robbing pollen from legume buds.
Sian Ka'an Biosphere Reserve, looking south. Atlantic Ocean on left, estuary on right. In estuary, red mangrove and sawgrass in foreground, hummock forest in background.


Bromeliad on flowering red mangrove. Stork Fresh water channel through mangroves over limestone.
Bletia sp. orchid. Poisonwood, Metopium sp., a relative of poison-ivy. Sub-humid forest of Cobá, sitting on a Post-Classical Mayan temple.


Namibia: Collecting Commiphora, January 2007

Andrea with Welwitschia mirabilis in the Namib desert. Commiphora glaucescens near Solitaire.
Commiphora giessi in Kaokoland. Commiphora saxicola near Brandberg (shrub)
Commiphora dinteri in the Namib desert. Commiphora saxicola in Kaokoland (tree) .
Commiphora namaensis near Orange River. Giant red sand dunes at Sossusvlei.
Lions sleeping in the road. Elephants at a water hole.
Commiphora gracilifrondosa Commiphora crenato-serrata


Maryland: Suitland Magnolia Bog, September 2006

Sarracenia purpurea (Sarraceniaceae) Osmunda cinnamomea (Osmundaceae)
Sarracenia and Eriocaulon decangulare (Ericocaulaceae) Virginia valeriae valeriae (Smooth Earth Snake) . I found two of these together on Smilax vines.
Viburnum nudum (Adoxaceae) Toxicodendron vernix (Anacardiaceae)


Tennessee: Smoky Mountains, April 2006

View of heath-balds on rockslides, remnants of dead and dying Abies fraseri and Picea rubens visible . Hardwood cove-forest, never logged.
Massive individuals of buckeye, Aesculus flava (Hippocastanaceae), grow in cove forests. An understory herb of the cove forest, Cardamine concatenata (Brassicaceae).
An other understory herb, Claytonia virginica (Portulaceae). A mesic hillside with Hepatica nobilis (Ranunculaceae), and the plantain-leaf sedge, Carex racemosa (Cyperaceae)
Viola rotundifolia (Violaceae) The water of the streams was remarkably clear.
Beautiful lichens of the heath balds.

Lichens and bryophyte of the heath balds.

Foliose bryophyte of the heath bald understory. Trunks of Rhododendron spp. visible in top left corner.

Beech gap forest (Fagus grandifolia) with Claytonia understory.


Viola rostrata (Violaceae) , note long floral spur. Viola canadensis (Violaceae)
Nurse log in spruce forest holding seedlings of hemlock (Tsuga canadensis). Hepatica nobilis (Ranunculaceae).
Phacelia fimbriata (Hydrophyllaceae). Another view of a heath bald.


Puerto Rico: Tropical Dry Forest, Guanica Biosphere Reserve, November 2005


Located in SW Puerto Rico, Guanica is a both a state forest and UNESCO Biosphere Reserve. It is a dry tropical forest home to endemic species of nightjars, woodpeckers, crested toads, and lizards.

My hosts from the University of Puerto Rico-Cayey: (L to R): Jose, Marcos Echegaray, Carlos Ricart, Harry Lopez. My field assistant: Glenn Montague.

Swietenia mahagoni (Mahogany; Meliaceae) capsules and winged seeds. It is a naturalized species in Puerto Rico. Guaiacum officinale (Lignum-vitae, Zygophyllaceae) dehisced fruit revealing red-colored aril.
View from Guanica showing range of habitats: low-stature woodlands to coastal plain. South America is beyond the horizon. Bursera simaruba (Almacigo; Burseraceae) is common in Guanica.
The coastal area of Guanica is uplifted ancient coral reef and extremely xeric. Asclepias purpurea (Milkweed; Asclepiadaceae) is a ca. 2 m woody perennial that grows in these coastal areas.
Margins of the sea subject to sea spray. Sesuvium portulacastrum in foreground. Close-up of succulent Sesuvium portulacastrum (Aizoaceae).
Melocactus intortus (Cactaceae) growing directly on limestone among low-growing button-wood mangrove bushes. Melocactus pushes its fruits up and out of the cephalium. They wind up resting on the spines or being eaten by birds (or botanists).
Close up of Conocarpus erectus (Button-wood mangrove, Combretaceae) and its button-like fruits. Endemic Puerto Rican Blue Tailed Ameiva (Teiidae, Ameiva wetmorei).

Puerto Rico: Tropical Rain Forest, El Yunque National Forest, November 2005

El Yunque, Caribbean National Forest is located in NE Puerto Rico. This is a view of one of the mountains within the park from mid elevation. Notice tree ferns in lower left. Forest within the park is stratified by elevation in four major groups: Tabonuco forest, Palo Colorado forest, Sierra Palm forest, and Cloud forest.
A young Dacryodes excelsa (Tabonuco, Burseraceae). Large terrestrial Camaenid snails.
Typical circinnate vernation of tree fern, Cyathea arborea (Cyatheaceae). Arboreal snail Gaeotis flavolineata. Notice its highly reduced shell.
Mt. Britton is named after a US botanist who collected in the area. It crosses through the Sierra Palm Forest into the Cloud Forest. Upper reaches of Sierra Palm (Prestoea montana, Palmae) forest
Ipomoea repanda (Bejuco colorado, Convolvulaceae).  
Fruit/Infloresence of Ficus (Fig, Moraceae) in cross-section, showing arrangement of white male flowers and tiny brown female flowers. Its pollination is dependent on wasps, whose larvae consume fig seeds. Reaching the summit of Mt. Britton in the clouds.
Andrea at the summit. Peaks of other mountains can be seen beyond. Looking down at clouds rushing over the mountain sides.