19Pepper Grass,46Peppermint,98Perfumed Cherry,54Periwinkle,90Petalostemum,60Petasites,130Petunia,101Phacelia,93Phleum,4Phlox,92Phragmites,6Phryma,107Phrymaceae,107Physalis,101Physocarpus,53Physostegia,99Phytolacca,30Phytolaccaceae,30Picea,1Pickerel-weed,10Pickerel-weed Family,10Picris,115Pignut Hickory,21Pigweed,30Pilea,24Pimpernel,87Pimpernel, False,104Pimpernel, Water,87Pinaceae,1Pin Cherry,54Pine,1Pine Drops,84Pine Family,1Pineweed,74Pinguicula,105Pink, Deptford,34Pink Family,31Pink, Fire,33Pink, Meadow,34Pink, Moss,92Pink, Mullein,33Pink, Rose,89Pin Oak,23Pinus,1Pinweed,74,75Piperaceae,19Pipewort,9Pipewort Family,9Pitcher Plant,48Pitcher Plant Family,48Plane Tree Family,51Plantaginaceae,107Plantago,107Plantain,107Plantain Family,107Plantain, Indian,122Plantain, Mud,10Platanaceae,51Platanus,51Plum,54Poa,7Podophyllum,40Podostemaceae,48Podostemum,48Pogonia,18Poison Hemlock,83Poison Ivy,69Poison Sumach,68Pokeweed,30Pokeweed Family,30Polanisia,47Polemoniaceae,92Polemonium,92Polemonium Family,92Polygala,65,66Polygalaceae,65Polygonatum,11Polygonaceae,25Polygonum,26-28Polymnia,123Polytaenia,81Pond Lily,35Pondweed,2Pondweed Family,2Pontederia,10Pontederiaceae,10Poplar,19Poppy,41Poppy, Celandine,41Poppy Family,41Poppy Mallow,73Populus,19Portulaca,34Portulacaceae,34Potamogeton,2Potentilla,52,55-57Prairie Clover,60Prairie Dock,122Prairie Fringed Orchis,19Prairie June-grass,6Prairie Parsnip,81Prenanthes,116Prickly Ash,65Prickly Pear,77Primrose,87Primrose Family,87Primula,87Primulaceae,87Prince's Feather,27Prince's Pine,85Proserpinaca,79Prunella,97Prunus,54Psedera,71Ptelea,65Pterospora,84Puccoon,94Pulse Family,58Purple Avens,57Purple Coneflower,131Purple Fringed Orchis,19Purslane,34Purslane Family,34Purslane, Water,78Putty Root,16Pyenanthemum,98Pyrola,84,85Pyrus,52,54,55Quack Grass,6Quaking Aspen,19Quassia Family,65Queen of the Prairie,57Quercus,22,23Radicula,43,45,46Radish,45Radish, Horse,46Radish, Wild,44,45Ragged Fringed Orchis,19Ragweed,114Ragwort,127,128Ram's Head Lady's Slipper,18Ranunculaceae,35Ranunculus,35-38Raphanus,44,45Raspberry,53,54Rattlebox,59Rattlesnake Master,80Rattlesnake Plantain,17Rattlesnake Root,116Red Ash,88Redbud,58Red Cedar,1Red Clover,61Red Currant,50Red Maple,70Red Mulberry,24Red Oak,23Red Raspberry,53Red-root,71Red Sorrel,25Red-top,6Reed,6Reed Grass,5Rein Orchis,18Reseda,48Resedaceae,48Rhamnaceae,71Rhamnus,71Rhexia,77Rhus,68,69Ribes,49,50River Weed,48River Weed Family,48Robinia,58Rock Cress,46,47Rocket, Sea,45Rock-rose Family,74Rosa,52Rosaceae,51Rose,52Rose Family,51Rose Mallow,72Rose Pink,89Rosin Weed,123Round-leaved Orchis,17Round-leaved Violet,75Rowan Tree,52Rubiaceae,108Rubus,53,54Rudbeckia,128Rue Anemone,39Rue Family,65Ruellia,107Rumex,25,26Rush,10Rush Family,10Rush, Twig,8Russian Thistle,28Rutabaga,43Rutaceae,65Sabbatia,89Sagina,32Sagittaria,3Salicaceae,19Salix,20Salmonberry,54Salsify,115Salsola,28Sambucus,109Samolus,87Sandalwood Family,24Sand Bur,5Sand Cherry,54Sand Rocket,42,43Sand Spurrey,32Sand Violet,76Sanguinaria,41Sanguisorba,57Sanicula,82Santalaceae,24Sapindaceae,70Saponaria,34Sarracenia,48Sarraceniaceae,48Sarsaparilla,80Sarsaparilla Family,80Sassafras,41Satureja,97Saururus,19Saxifraga,50Saxifragaceae,49Saxifrage,50Saxifrage Family,49Saxifrage, Golden,50Scarlet Oak,23Scheuchzeria,3Schneck's Oak,23Scirpus,7Scleranthus,31Scorpion Grass,94Scrophularia,103Scrophulariaceae,101Scrub Oak,23Scutellaria,96Sea Rocket,45Sea-side Crowfoot,36Sedge,8Sedge Family,7Sedum,48,49Self-heal,97Seneca Snakeroot,66Senecio,127,128Senna, Wild,60Setaria,4Shag-bark Hickory,21Sheep-berry,111Sheep Laurel,85Shepherdia,77Shepherd's Purse,46Shingle Oak,22Shin-leaf,84,85Shooting Star,87Showy Lady's Slipper,18Showy Orchis,17Sicyos,112Sida,72,73Silene,33,34Silphium,122,123,127Silver Maple,70Silver Weed,55Silvery Cinquefoil,66Silybum,117Simarubaceae,65Sium,81Sisymbrium,43-45,47Sisyrinchium,15Skullcap,96Skunk Cabbage,8Skunk Currant,49Slender Nettle,24Slippery Elm,24Slough Grass,5Small-flowered Crowfoot,36Small-fruited Hickory,21Small Snapdragon,103Small Solomon's Seal,11Smartweed,27,28Smilacina,14Smilax,11Smooth Alder,22Snake Mouth,18Snakeroot, Black,82Snakeroot, Seneca,66Snakeroot, Virginia,25Snapdragon,103Sneezeweed,127Sneeze Weed,128Sneezewort,131Snowberry,85,111Soapberry Family,70Soapwort,34Solanaceae,100Solanum,100Solidago,125-127Solomon's Seal,11Sorbaria,57Sorrel, Red,25Sorrel, Green,25Sorrel, Wood,64Sour Dock,26Sour Gum,83Southernwood,119Sparganiaceae,2Spartina,5Spear Grass,7Spearmint,98Spearwort,36Speckled Alder,22Specularia,112Speedwell,105Spergula,32Spergularia,32Spice Bush,41Spiderwort,9Spiderwort Family,9Spikenard,80Spike Rush,7Spiraea,53Spiranthes,16Spirodela,9Spotted Wintergreen,85Spurge,67,68Spurge Family,66Spurred Gentian,89Spurrey,32Spring Avens,56Spring Beauty,34Spring Vetch,59Spruce,1Squashberry,111Squaw-root,106Squaw Weed,128Squirrel Corn,41Squirrel-tail,4Stachys,99Staff Tree Family,69Staphylea,69Staphyleaceae,69Star Flower,87Star Grass,14Star of Bethlehem,14Starry Campion,33Steironema,88Stellaria,32,33Stemless Lady's Slipper,18Stickseed,94Stinging Nettle,24Stitchwort,32St. John's-wort,73,74St. John's-wort Family,73Stone Clover,61Stonecrop,48Stonecrop, Ditch,49Stork's-bill,64Strawberry,56Strawberry, Barren,55Strawberry Blite,29Streptopus,11Striped Maple,70Strophostyles,58Stylophorum,41Sugar Maple,70Sumach,68,69Summer Grape,72Summer Savory,97Sundew,48Sundew Family,48Sundrops,78Sunflower,128-130Sunflower, Tickseed,124Swamp Birch,22Swamp Currant,49Swamp Dewberry,53Swamp Laurel,