Witchweed _Striga lutea_ 54 Wolffia _Wolffia_ 30 Wolftail _Lycurus_ 22 Woodfern _Dryopteris_ 28 Woodnettle _Laportea_ 46 Woodreed _Cinna_ 20 Woodsia _Woodsia_ 28 Yam _Dioscorea_ 29 Yarrow _Achillea_ 35 Yerbadetajo _Eclipta alba_ 41 Zinnia _Zinnia_ 55 Zizia _Zizia_ 55 Zoysia _Zoysia_ 26 =GRASSES= _Aegilops cylindrica_ Host goatgrass _Agropyron_ Gaertn. wheatgrass _cristatum_[9] (L.) Gaertn. fairway w. _dasystachyum_ (Hook.) Scribn. thickspike w. _desertorum_[9] (Fisch.) Schult. crested w. _elongatum_[10] (Host) Beauv. tall w. _inerme_ (Scribn. & Smith) Rydb. beardless w. _intermedium_[11] (Host) Beauv. intermediate w. _repens_ (L.) Beauv. quackgrass _riparium_ Scribn. & Smith streambank w. _semicostatum_ (Steud.) Nees ex Boiss. drooping w. _sibiricum_ (Willd.) Beauv. Siberian w. _smithii_ Rydb. western w. _spicatum_ (Pursh) Scribn. & Smith bluebunch w. _subsecundum_ (Link) Hitchc. bearded w. _trachycaulum_ (Link) Malte slender w. _trichophorum_[11] (Link) Richt. pubescent w. _Agrostis_ L. bentgrass _alba_ L. redtop _canina_ L. velvet b. _diegoensis_ Vasey thin b. _exarata_ Trin. spike b. _hiemalis_ (Walt.) B.S.P. winter b. _palustris_ Huds. creeping b. _tenuis_ Sibth. colonial b. var. _aristata_ (Parnell) Druce awned c. b. _Aira caryophyllea_ L. silver hairgrass _Alopecurus_ L. foxtail _aequalis_ Sobol. shortawn f. _arundinaceus_ Poir. creeping f. _carolinianus_ Walt. Carolina f. _myosuroides_ Huds. mouse f. _pratensis_ L. meadow f. _Ammophila_ Host beachgrass