17 Pa. Code § 45.21
Plant species classified as Tentatively Undetermined are as follows:
| Scientific Name | Common Name |
| Agalinis obtusifolia Raf. | False-Foxglove |
| Amelanchier humilis Wiegand | Low Serviceberry |
| Amelanchier obovalis (Michx.) Ashe | Coastal Juneberry |
| Amelanchier sanguinea (Pursh) DC. | Roundleaf Juneberry |
| Andropogon glomeratus (Walter) Britton, Stearns & Poggenb. | Bushy Bluestem |
| Antennaria solitaria Rydb. | Single-Headed Pussy-Toes |
| Arabis hirsuta (L.) Scop. | Western Hairy Rock-Cress |
| Aristida dichotoma Michx. var. curtissii A. Gray | Poverty Grass |
| Aristida longespica Poir. var. geniculata (Raf.) Fernald | Long-Spike Three-Awned Grass |
| Aristolochia macrophylla Lam. | Pipevine |
| Carex crawfordii Fernald | Crawford’s Sedge |
| Carex haydenii Dewey | Cloud Sedge |
| Carex limosa L. | Mud Sedge |
| Carex meadii Dewey | Mead’s Sedge |
| Chasmanthium latifolium (Michx.) H. O. Yates | Wild-Oats |
| Chenopodium capitatum (L.) Asch. | Strawberry Goosefoot |
| Crataegus brainerdii Sarg. | Brainerd’s Hawthorne |
| Crataegus mollis (Torr. & A. Gray) Scheele | Downy Hawthorne |
| Cuscuta cephalanthi Engelm. | Buttonbush Dodder |
| Cuscuta polygonorum Engelm. | Smartweed Dodder |
| Cyperus tenuifolius (Steud.) Dandy | Thin-Leaved Flatsedge |
| Cystopteris laurentiana (Weath.) Blasdell | Laurentian Bladder-Fern |
| Desmodium glabellum (Michx.) Kuntze | Tall Tick-Trefoil |
| Desmodium nuttallii (Schindl.) Schub. | Nuttall’s Tick-Trefoil |
| Dichanthelium annulum (Ashe) LeBlond | Annulus Panic Grass |
| Dichanthelium boreale (Nash) Freckmann | Northern Panic Grass |
| Dichanthelium commonsianum (Ashe) Freckmann | Cloaked Panic Grass |
| Dichanthelium lucidum (Ashe) LeBlond | Shining Panic Grass |
| Dichanthelium villosissimum (Nash) Freckmann | Long-Haired Panic Grass |
| Dichanthelium yadkinense (Ashe) Mohlenbr. | Yadkin River Panic Grass |
| Dracocephalum parviflorum Nutt. | American Dragonhead |
| Epilobium palustre L. | Marsh Willow-Herb |
| Eupatorium rotundifolium L. | Round-Leaved Thoroughwort |
| Filipendula rubra (Hill) B. L. Rob. | Queen-of-the-Prairie |
| Gentiana alba Muhl. ex Nutt. | Yellow Gentian |
| Gentiana saponaria L. | Soapwort Gentian |
| Gentiana villosa L. | Striped Gentian |
| Glyceria acutiflora Torr. | Sharp-Flowered Manna-Grass |
| Gymnocarpium appalachianum K. M. Pryer & Haufler | Appalachian Oak Fern |
| Houstonia purpurea L. var. purpurea | Purple Bluets |
| Hypericum drummondii (Grev. & Hook) Torr. & A. Gray | Nits-and-Lice |
| Lathyrus palustris L. | Vetchling |
| Lemna turionifera Landolt | Winter Duckweed |
| Leucothoe racemosa (L.) A. Gray | Swamp Dog-Hobble |
| Liatris scariosa (L.) Willd. | Northern Blazing-Star |
| Lonicera hirsuta Eaton | Hairy Honeysuckle |
| Luzula bulbosa (A. W. Wood) Rybd. | Wood-Rush |
| Malaxis monophyllos (L.) Swartz var. brachypoda (A. Gray) F. Morris & E. A. Eames | White Adder’s-Mouth |
| Meehania cordata (Nutt.) Britton | Heart-Leafed Meehania |
| Muhlenbergia cuspidata (Torr.) Rydb. | Sharp-Pointed Muhly |
| Nuphar microphylla (Pers.) Fernald | Small Yellow Pond-Lily |
| Oenothera pilosella Raf. | Evening-Primrose |
| Oxypolis rigidior (L.) Raf. | Stiff Cowbane |
| Packera plattensis (Nutt.) W. A. Weber & Á Löve | Prairie Ragwort |
| Panicum flexile (Gatt.) Scribn. | Wiry Witchgrass |
| Panicum longifolium Torr. | Long-Leaved Panic Grass |
| Paronychia fastigiata (Raf.) Fernald var. nuttallii (Small) Fernald | Whitlow Wort |
| Parthenium intergrifolium L. | American Fever-Few |
| Paspalum floridanum (Michx.) var. glabratum Engelm. ex Vasey | Florida Beadgrass |
| Paspalum laeve (Michx.) var. pilosum Scribn. | Field Beadgrass |
| Paspalum setaceum Michx. | Slender Beadgrass |
| Phlox pilosa L. | Downy Phlox |
| Phyla lanceolata (Michx.) Greene | Lance Fog-Fruit |
| Physalis virginiana Mill. | Virginia Ground-Cherry |
| Platanthera hookeri (Torr. ex Gray) Lindl. | Hooker’s Orchid |
| Pluchea odorata (L.) Cass. | Shrubby Camphor-Weed |
| Poa languida A. Hitchc. | Drooping Bluegrass |
| Podostemum ceratophyllum Michx. | Riverweed |
| Polygala polygama Walter | Racemed Milkwort |
| Polygonella articulata (L.) Meisn. | Eastern Jointweed |
| Polygonum amphibium L. var. stipulaceum (Coleman) Fern. | Stipuled Water-Smartweed |
| Polygonum ramosissimum Michx. | Bushy Knotweed |
| Potamogeton filiformis Pers. var. borealis (Raf.) St. John | Slender Pondweed |
| Potamogeton oakesianus J. W. Robbins | Oakes’ Pondweed |
| Potamogeton perfoliatus L. | Clasping-Stemmed Pondweed |
| Pycnanthemum verticillatum (Michx.) Pers. var. pilosum (Nutt.) Cooperr. | Hairy Mountain-Mint |
| Ranunculus aquatilis L. var. diffusus With. | White Water-Crowfoot |
| Ranunculus flammula L. | Lesser Spearwort |
| Rhamnus alnifolia L’ Hér | Alder-Leaved Buckthorn |
| Rhynchospora recognita (Gale) Kral | Small Globe Beak-Rush |
| Ribes lacustre (Pers.) Poir. | Swamp Currant |
| Rosa virginiana P. Mill. | Virginia Rose |
| Rubus setosus Bigelow | Small Bristleberry |
| Rumex hastatulus Baldwin ex Elliott | Heart Sorrell |
| Samolus parviflorus Raf. | Pineland Pimpernel |
| Saxifraga micranthidifolia (Haw.) Steud. | Lettuce Saxifrage |
| Scleria triglomerata Michx. | Whip Nut-Rush |
| Scutellaria saxatilis Riddell | Rock Skullcap |
| Senna marilandica (L.) Link | Wild Senna |
| Sisyrinchium albidum Raf. | Blue-Eyed-Grass |
| Solidago rigida L. | Hard-Leaved Goldenrod |
| Spiranthes tuberosa Raf. | Slender Ladies’-Tresses |
| Stachys hyssopifolia Michx. | Hyssop Hedge-Nettle |
| Stylosanthes biflora (L.) Britton, Stearns & Poggenb. | Pencil-Flower |
| Symphyotrichum dumosum (L.) Nesom | Bushy Aster |
| Symphyotrichum ericoides (L.) Nesom | White Heath Aster |
| Taxus canadensis Marsh. | American Yew |
| Trillium flexipes Raf. | Declined Trillium |
| Triosteum angustifolium L. | Horse Gentian |
| Tripsacum dactyloides (L.) L. | Eastern Gammagrass |
| Uvularia pudica Michx. | Mountain Bellwort |
| Viburnum trilobum Marshall | Highbush-Cranberry |
| Viola renifolia A. Gray | Kidney-Leaved Violet |
| Vitis cinerea (Englem. in A. Gray) Englem. ex Millardet var. baileyana (Munson) Comeaux | Possum-Grape |
| Wolffia borealis (Engelm.) Landolt | Dotted Dotted Watermeal |
The provisions of this § 45.21 amended under section 7 of the Wild Resource Conservation Act (32 P.S. § 5307); and sections 305(a)(9) and 313(g) of the Conservation and Natural Resources Act (71 P.S. § § 1340.305(a)(9) and 1340.313(g)).
The provisions of this § 45.21 adopted December 4, 1987, effective January 1, 1988, 17 Pa.B. 5027; amended June 18, 1993, effective June 19, 1993, 23 Pa.B. 2816; amended December 21, 2018, effective December 22, 2018, 48 Pa.B. 7757; amended September 22, 2023, effective September 23, 2023, 53 Pa.B. 5892. Immediately preceding text appears at serial pages (394753) to (394758).