Checklist for Bot. Soc. Washington Potomac Spring Wildflower Foray to Bear Island "*" = introduced. Average fl. dates from Shetler & Wiser. 1987. First flowering dates for spring-blooming plants of the Washington DC area for the years 1970-1983. Proc. Bioi. Soc. Washington 100: 993-1017. See also http://www.nmnh.sLedu/botany/projects/dcflora/springfloweringrecords.htm Suggested notes: (1) where (p=parking, tp=towpath, begin, rocks, return) (2) stage fl. or fr. (early, peak, late)

GYMNOSPERMS anise) [spreading pubescence] 4/24 *Cardamine hirsuta (bitter cress) [lvs PINACEAE Osmorhiza longistylis (sweet cicily) pinnate] 2/27 Pinus virginiana (scrub pine) 5/7 [appressed pubescence] 4/25 *Erysimum repandum (treacle-mustard) MONOCOT FAMILIES Zizia aurea (golden alexander) 4/15 [hairs 2-5-branched] ARACEAE AQUIFOLIACEAE *Lepidium campestre (fieldcress) [stem Arisaema triphyllum (Jack-in-thepulpit) Ilex opaca (american holly) 5/14 Ivs auricled] 4/30 4/22 ARISTOLOCHIACEAE Lepidium virginicum (wild peppergrass) CYPERACEAE Asarum canadense (wild ginger) 4/14 [stem Ivs tapering] 4/22 Carex albicans ASTERACEAE (COMPOSITAE) CACTACEAE Carex careyana (sedge) Antennaria plantaginifolia (pussytoes, Opuntia humifusa (eastern prickly pear) Carex nigromarginata everlasting) 4/16 5/30 Carex pensylvanica? (sedge) 4/14 (early Arnica acaulis (leopard's bane) CAPRIFOLIACEAE fl.) Erigeron philadelphicus (common *Lonicera japonica (honeysuckle) 5/11 JUNCACEAE f1eabane) 5/8 *Lonicera maackii (Amur honeysuckle) Luzula echinata (wood rush) Apr Hieracium venosum (veiny hawkweed) 5/23 LILIACEAE 5/13 *Lonicera xylostemon (European fly- Erythronium albidum (white trout-lily) Krigia virginica (Virginia dwarfdandelion) honeysuckle) 4 4/15 Senecio aureus [=Packera] (golden Viburnum acerifolium (maple-leaved Erythronium americanum (yellow trout ragwort) 4/12 viburnum) [lvs 3-lobed] 4/19 lily) 4/1 Taraxacum officinale (dandelion) 2/1 Viburnum prunifolium [Ivs fine toothed, *Muscari botryoides (grape hyacinth) 4/6 Tussilago farfara (coltsfoot ) veins small (blackhaw) 4/25 Polygonatum biflorum (solomon's seal) BERBERIDACEAE Viburnum rafinesqueanum (downy arrow- 5/10 Jeffersonia diphylla (twin-leaf) 4/6 wood) [Ifs big-toothed, veins Smilax spp. (greenbriars) Podophyllum peltatum (may-apple) 4/27 prominent] Smilacina racemosa (false solomon's BETULACEAE CARYOPHYLLACEAE seal) 5/9 Alnus serrulata (alder) 3/10 Cerastium arvense (field chickweed) Trillium sessile (toad trillium) 4/8 Carpinus caroliniana (hornbeam, [styles 5, petals> sepals] 4/25 Uvularia sessilifolia (bellwort) 5/2 musclewood) 4/10 *Cerastium vulgatum (common mouse- POACEAE (GRAMINEAE) Ostrya virginiana (hop hornbeam, iron eared chickweed) [styles 5, petals = Anthoxanthum odoratum (sweet vernal wood) 4/15 sepals] Apr grass) 4/22 BORAGINACEAE Silene caroliniana (wild pink) [sepals Poa annua (annual bluegrass) 3/23 Mertensia virginica (bluebells) 4/2 connate] 4/19 Poa cuspidata (? bluegrass) 4/12 BRASSICACEAE (CRUCIFERAE) *Stellaria media (common chickweed) Poa sylvestris (bluegrass) May? *Alliaria petiolata (garlic mustard) 4/15 [styles 3, Ivs petiolate, 1-3 cm] 1/28 DICOT FAMILIES Arabis laevigata (smooth rock cress) Stellaria pubera (star chickweed) [styles ACERACEAE [lower Ivs toothed] 4/3 3, Ivs subsessile, 2-9 cm] 4/8 Acer negundo (box elder, ash-leaved Arabis lyrata (lyre-leaved rock cress CELASTRACEAE maple) 4/4 [lower Ivs pinnate] 4/11 *Euonymus alata (winged burning bush) Acer rubrum (red maple) 3/11 *Barbarea vulgaris (winter cress) 4/14 5/5 Acer saccharinum (silver maple) 2/22 *Capsella bursa-pastoris (shepherd's CORNACEAE Acer saccharum (sugar maple) 4/12 purse) 3/28 Cornus florida (flowering dogwood) 4/21 ANACARDIACEAE Cardamine angustata [Dentaria CRASSULACEAE Rhus glabra (smooth sumac) heterophylla] (slender toothwort) Sedum ternatum (3-branched stonecrop) Rhus typhina (staghorn sumac) 5/28 [glabrous, lflt teeth short, rounded] 5/2 Toxicodendron radicans (poison ivy) 5/16 4/5 ERICACEAE ANNONACEAE Cardamine arenicola (tiny sand cress) Epigaea repens (trailing arbutus) 4/4 Asimina triloba (paw-paw) 4/25 Cardamine bulbosa (spring cress) [lvs Gaylussacia baccata (black huckleberry) APIACEAE (UMBELLIFERAE) simple] 4/17 [lower If surface with wax globules] Erigenia bulbosa (harbinger-ofspring) Cardamine concatenata [Dentaria laciniata] 5/13 3/16 (cut-leaved toothwort) [hairy, lflt Kalmia latifolia (sheepkill) 5/20 Osmorhiza claytonii (sweet cicely, wild teeth long, acute] 3/25 Rhododendron periclymenoides (pinxter) 4/30 OLEACEAE Rubus flagellaris? (northern dewberry) Vaccinium pallidum (low blueberry) [V. Chionanthus virginicus (fringetree) 5/10 5/9 vacillans; stamen tips included] 4/26 Fraxinus americana (white ash) [glabrous] RUBIACEAE Vaccinium stamineum (deerberry) 4/8 *Galium aparine (bedstraw) 4/29 [stamen tips exserted] 5/6 Fraxinus pensylvanica [hairy] (red ash) Houstonia caerulea (bluets) 4/4 FABACEAE (LEGUMINOSAE) OROBANCHACEAE Mitchella repens (partridge-berry) 5/29 Cercis canadensis (redbud) 4/12 Conopholis americana (squaw-root) 5/5 RUTACEAE Robinia pseudoacacia (black locust) 5/7 Orobanche uniflora (cancer root) 5/8 Ptelea trifoliata (hop-tree) [Ivs alt., 3- FAGACEAE OXALIDACEAE foliolate] 5/23 Quercus alba (white oak) 4/26 Oxalis stricta? (common wood-sorrel) 5/8 SALICACEAE Quercus palustris (pin oak) 4/17 Oxalis violacea (violet wood-sorrel) 5/11 Populus deltoides (cottonwood) 4/8 Quercus phellos (willow oak) 4/27 PAPAVERACEAE Salix nigra (black willow) 4/26 Quercus montana [Q. prinus auct., not Sanguinaria canadensis (bloodroot) 3/26 SANTALACEAE L.] (chestnut oak) 4/29 PLATANACEAE Comandra umbellata (bastard toadflax) Quercus rubra [Q. borealis] (northern red Platanus occidentalis (sycamore) 4/30 5/7 oak) 4/13 POLEMONIACEAE SAXIFRAGACEAE FUMARIACEAE Phlox divaricata (blue phlox) 4/11 Heuchera americana (alumroot) 5/17 Corydalis flavula (corydalis) 4/8 Phlox subulata (mosspink) 3/16 Saxifraga virginiensis (early saxifrage) Dicentra canadensis (squirrel corn) 4/12 PORTULACEAE 3/31 Dicentra cucullaria (dutchman's breeches) Claytonia virginica (spring beauty) 3/15 SCROPHULARIACEAE 4/3 PYROLACEAE *Paulownia tomentosa (empress tree) 5/2 GERANIACEAE Chimaphila umbellata (pipsissewa) *Veronica hederifolia (ivy-leafed Geranium maculatum (crane's bill, wild RANUNCULACEAE speedwell) 3/18 geranium) 4/22 Anemone americana [Hepatica] (hepatica) Veronica persica (speedwell) HYDROPHYLLACEAE 3/16 SIMAROUBACEAE Ellisia nyctelea (ellisia) [fls solitary, opp. Anemone quinquefolia (wood anemone) *Ailanthus altissima (tree-ofheaven) 5/27 Ivs.) 4/20 STAPHYLEACEAE Hydrophyllum canadense (waterleaf) 5/9 Aquilegia canadensis (columbine) 4/21 Staphylea trifolia (bladdernut) [Ivs opp. [perennial] Ranunculus abortivus (smallflowered 3-foliolate] 4/22 Phacelia coveillei (small-flowered crowfoot) basal lvs subentire ] 4/7 THYMELAEACEAE phacelia) [filaments glabrous, *Ranunculus bulbosus (bulbous Dirca palustris (leatherwood) 3/26 endemic] buttercup) [stem bulblike at base] TILIACEAE Phacelia dubia [filaments villous] 5/5 4/21 Tilia americana (basswood) 5/31 Phacelia purshii (miami mist) [petals *Ranunculus ficaria (lesser celadine) ULMACEAE fringed] 4/25 [sepals 3-4] Celtis occidentalis (hackberry) 4/29 Phacelia ranunculacea (phacelia) 4/25 Ranunculus hispidus var. nitidus (swamp Ulmus americana (american elm) 3/2 HYPERICACEAE buttercup) [R. septentrionalis] [basal Ulmus rubra (slippery elm) 4/11 Hypericum prolificum (shrubby St.John's & cauline Ivs alike] 4/13 VIOLACEAE wort) 7 Thalictrum thalictroides [Anemonella] Hybanthus concolor (green violet) 5/7 JUGLANDACEAE (rue anemone) 4/7 Viola bicolor (field pansy, stemmed Carya (hickory) 5/1-5 ROSACEAE white violet) [V. rafinesquii] 4/8 LAMIACEAE (LABIATAE) Amelanchier arborea (downy serviceberry) Viola pubescens (stemmed yellow violet) *Glechoma hederacea [Nepeta hederacea] 4/5 [infl. lax, lvs tomentose beneath] [V. pensylvanica] 4/14 (gill-over-the-ground, ground ivy) Amelanchier canadensis (shadbush) 4/9 Viola sororia (common blue violet) [V. 3/31 [infl. ascending] papilionacea] 4/3 *Lamium purpureum (purple dead-nettle) Amelanchier laevis (smooth serviceberry) Viola striata (stemmed creamy violet) 3/19 4/20 [infl. lax, Ivs glabrous beneath] 4/18 LAURACEAE *Duchesnea indica (false strawberry) Lindera benzoin (spicebush) 3/27 [bractlets 3-toothed; lfts 3] 3/21 Records from Dan H. Nicolson, various Sassafras albidum (sassafras) 4/11 *Malus sylvestris (apple) 4/15 lists through 8 Apr. 2008 LlMNANTHACEAE Potentilla canadensis (running cinquefoil) Floerkea proserpinacoides (false mermaid) [bractlets entire, Iflts 5] 4/18 [fls 3-merous] 4/18 Prunus americana [infl. subumbellate] MAGNOLIACEAE (wild plum) 4/3 Liriodendron tulipifera (tulip poplar) 5/8 *Prunus avium [infl. sub umbellate] NYSSACEAE (sweet cherry) Nyssa sylvatica (black gum, pepperidge) Prunus serotina (black cherry) [infl. 5/15 racemose] 5/5