Rare Species by County: Worcester
Last Updated on 3/1/2003
| Taxonomic Group | Scientific Name | Common Name | State Rank | Federal Rank | Most Recent Obs |
| Fish | Lampetra appendix | American Brook Lamprey | T | 1994 | |
| Fish | Notropis bifrenatus | Bridle Shiner | SC | 1996 | |
| Amphibian | Ambystoma jeffersonianum | Jefferson Salamander | SC | 1999 | |
| Amphibian | Ambystoma laterale | Blue-Spotted Salamander | SC | 2001 | |
| Amphibian | Ambystoma opacum | Marbled Salamander | T | 2001 | |
| Amphibian | Gyrinophilus porphyriticus | Spring Salamander | SC | 1999 | |
| Amphibian | Hemidactylium scutatum | Four-Toed Salamander | SC | 2001 | |
| Reptile | Clemmys guttata | Spotted Turtle | SC | 2001 | |
| Reptile | Clemmys insculpta | Wood Turtle | SC | 2001 | |
| Reptile | Emydoidea blandingii | Blanding's Turtle | T | 2001 | |
| Reptile | Terrapene carolina | Eastern Box Turtle | SC | 1999 | |
| Bird | Accipiter striatus | Sharp-Shinned Hawk | SC | (PS) | 1987 |
| Bird | Ammodramus henslowii | Henslow's Sparrow | E | 1974 | |
| Bird | Ammodramus savannarum | Grasshopper Sparrow | T | (PS) | 1994 |
| Bird | Asio otus | Long-Eared Owl | SC | 1978 | |
| Bird | Bartramia longicauda | Upland Sandpiper | E | 1994 | |
| Bird | Botaurus lentiginosus | American Bittern | E | 2000 | |
| Bird | Circus cyaneus | Northern Harrier | T | 1990 | |
| Bird | Cistothorus platensis | Sedge Wren | E | 2001 | |
| Bird | Falco peregrinus | Peregrine Falcon | E | (PS:LE) | 1937 |
| Bird | Gallinula chloropus | Common Moorhen | SC | (PS) | 1988 |
| Bird | Gavia immer | Common Loon | SC | 2000 | |
| Bird | Haliaeetus leucocephalus | Bald Eagle | E | (PS:LT,PDL) | 2001 |
| Bird | Ixobrychus exilis | Least Bittern | E | 1999 | |
| Bird | Podilymbus podiceps | Pied-Billed Grebe | E | 1993 | |
| Bird | Pooecetes gramineus | Vesper Sparrow | T | 1981 | |
| Bird | Rallus elegans | King Rail | T | 1999 | |
| Bird | Vermivora chrysoptera | Golden-Winged Warbler | E | 1986 | |
| Mammal | Myotis sodalis | Indiana Myotis | E | LE | 1938 |
| Mammal | Sorex palustris | Water Shrew | SC | 1999 | |
| Mammal | Synaptomys cooperi | Southern Bog Lemming | SC | 1898 | |
| Sponge | Spongilla aspinosa | Smooth Branched Sponge | SC | 1989 | |
| Mussel | Alasmidonta undulata | Triangle Floater | SC | 2002 | |
| Mussel | Alasmidonta varicosa | Brook Floater (Swollen Wedgemussel) | E | 1859 | |
| Mussel | Strophitus undulatus | Creeper | SC | 2002 | |
| Crustacean | Crangonyx aberrans | Mystic Valley Amphipod | SC | 2001 | |
| Crustacean | Eubranchipus intricatus | Intricate Fairy Shrimp | SC | 1998 | |
| Dragonfly/Damselfly | Aeshna mutata | Spatterdock Darner | E | 1999 | |
| Dragonfly/Damselfly | Aeshna subarctica | T | 2001 | ||
| Dragonfly/Damselfly | Enallagma carunculatum | Tule Bluet | SC | ||
| Dragonfly/Damselfly | Enallagma laterale | New England Bluet | SC | 1999 | |
| Dragonfly/Damselfly | Enallagma recurvatum | Pine Barrens Bluet | T | 1999 | |
| Dragonfly/Damselfly | Gomphus borealis | Beaverpond Clubtail | SC | 1992 | |
| Dragonfly/Damselfly | Gomphus descriptus | Harpoon Clubtail | E | 2001 | |
| Dragonfly/Damselfly | Neurocordulia obsoleta | Umber Shadowdragon | SC | 1917 | |
| Dragonfly/Damselfly | Ophiogomphus aspersus | Brook Snaketail | SC | 1995 | |
| Dragonfly/Damselfly | Somatochlora elongata | Ski-Tailed Emerald | SC | 1999 | |
| Dragonfly/Damselfly | Somatochlora forcipata | SC | 2001 | ||
| Dragonfly/Damselfly | Somatochlora incurvata | T | 1998 | ||
| Dragonfly/Damselfly | Somatochlora linearis | Mocha Emerald | SC | 2001 | |
| Dragonfly/Damselfly | Stylurus scudderi | Zebra Clubtail | E | 2001 | |
| Dragonfly/Damselfly | Stylurus spiniceps | A Clubtail Dragonfly | T | 2001 | |
| Beetle | Cicindela duodecimguttata | Twelve-Spotted Tiger Beetle | SC | 1944 | |
| Beetle | Cicindela purpurea | Purple Tiger Beetle | SC | 1999 | |
| Beetle | Desmocerus palliatus | Elderberry Long-Horned Beetle | SC | 1998 | |
| Butterfly/Moth | Callophrys hesseli | Hessel's Hairstreak | SC | 2001 | |
| Butterfly/Moth | Cingilia catenaria | Chain Dot Geometer | SC | 1927 | |
| Butterfly/Moth | Eacles imperialis | Imperial Moth | T | 1934 | |
| Butterfly/Moth | Hemaris gracilis | Slender Clearwing Sphinx Moth | SC | 2001 | |
| Butterfly/Moth | Itame sp 1 nr inextricata | Pine Barrens Itame | SC | 1992 | |
| Butterfly/Moth | Metarranthis pilosaria | Coastal Swamp Metarranthis Moth | SC | 1999 | |
| Butterfly/Moth | Rhodoecia aurantiago | A Noctuid Moth | T | 2002 | |
| Butterfly/Moth | Satyrium favonius | Oak Hairstreak | SC | 2001 | |
| Butterfly/Moth | Zanclognatha martha | Pine Barrens Zanclognatha | T | 1994 | |
| Vascular Plant | Acer nigrum | Black Maple | SC | 1929 | |
| Vascular Plant | Adlumia fungosa | Climbing Fumitory | T | 2000 | |
| Vascular Plant | Alnus viridis ssp crispa | Mountain Alder | T | 1932 | |
| Vascular Plant | Amelanchier bartramiana | Bartram's Shadbush | T | 2000 | |
| Vascular Plant | Amelanchier sanguinea | Roundleaf Shadbush | SC | 1947 | |
| Vascular Plant | Arabis laevigata | Smooth Rock-Cress | T | 1998 | |
| Vascular Plant | Arabis lyrata | Lyre-Leaved Rock-Cress | E | 1951 | |
| Vascular Plant | Arceuthobium pusillum | Dwarf Mistletoe | SC | 2000 | |
| Vascular Plant | Asclepias purpurascens | Purple Milkweed | E | 1954 | |
| Vascular Plant | Asplenium montanum | Mountain Spleenwort | E | 1946 | |
| Vascular Plant | Cardamine longii | Long's Bitter-Cress | E | 1923 | |
| Vascular Plant | Carex backii | Back's Sedge | E | 1997 | |
| Vascular Plant | Carex lenticularis | Shore Sedge | T | 1933 | |
| Vascular Plant | Carex michauxiana | Michaux's Sedge | E | 1928 | |
| Vascular Plant | Carex polymorpha | Variable Sedge | E | 2001 | |
| Vascular Plant | Carex tuckermanii | Tuckerman's Sedge | E | 1931 | |
| Vascular Plant | Carex typhina | Cat-Tail Sedge | T | 1999 | |
| Vascular Plant | Cimicifuga racemosa | Black Cohosh | E | 1937 | |
| Vascular Plant | Clematis occidentalis | Purple Clematis | SC | 2000 | |
| Vascular Plant | Conioselinum chinense | Hemlock Parsley | SC | 1918 | |
| Vascular Plant | Corallorhiza odontorhiza | Autumn Coralroot | SC | 2001 | |
| Vascular Plant | Cyperus houghtonii | Houghton's Flatsedge | E | 1991 | |
| Vascular Plant | Desmodium humifusum | Spreading Tick-Trefoil | E | 1988 | |
| Vascular Plant | Doellingeria infirma | Cornel-Leaved Aster | E | 1898 | |
| Vascular Plant | Eleocharis obtusa var ovata | Ovate Spike-Sedge | E | 1991 | |
| Vascular Plant | Elymus villosus | Hairy Wild Rye | E | 1998 | |
| Vascular Plant | Eragrostis frankii | Frank's Lovegrass | SC | 1939 | |
| Vascular Plant | Eriophorum gracile | Slender Cottongrass | T | 2000 | |
| Vascular Plant | Goodyera repens | Dwarf Rattlesnake-Plantain | E | 1931 | |
| Vascular Plant | Hydrophyllum canadense | Broad Waterleaf | E | 1943 | |
| Vascular Plant | Isoetes lacustris | Lake Quillwort | E | 1922 | |
| Vascular Plant | Juncus filiformis | Thread Rush | E | 1987 | |
| Vascular Plant | Liatris borealis | New England Blazing Star | SC | 1999 | |
| Vascular Plant | Lipocarpha micrantha | T | 1990 | ||
| Vascular Plant | Lycopodiella alopecuroides | Foxtail Clubmoss | E | 1999 | |
| Vascular Plant | Lygodium palmatum | Climbing Fern | SC | 1999 | |
| Vascular Plant | Malaxis bayardii | Bayard's Green Adder's-Mouth | E | 1999 | |
| Vascular Plant | Milium effusum | Woodland Millet | T | 2001 | |
| Vascular Plant | Myriophyllum alterniflorum | Alternate-Flowered Water-Milfoil | T | 1898 | |
| Vascular Plant | Nuphar microphylla | Tiny Cow-Lily | E | 1950 | |
| Vascular Plant | Ophioglossum pusillum | Adder's-Tongue Fern | T | 2001 | |
| Vascular Plant | Oxalis violacea | Violet Wood-Sorrel | E | 1882 | |
| Vascular Plant | Panicum philadelphicum | Philadelphia Panic-Grass | SC | 1995 | |
| Vascular Plant | Pedicularis lanceolata | Swamp Lousewort | E | 1940 | |
| Vascular Plant | Penstemon hirsutus | Hairy Beardtongue | E | 1932 | |
| Vascular Plant | Petasites frigidus var palmatus | Sweet Coltsfoot | E | 1912 | |
| Vascular Plant | Platanthera dilatata | Leafy White Orchis | T | 1904 | |
| Vascular Plant | Platanthera flava var herbiola | Pale Green Orchis | T | 1946 | |
| Vascular Plant | Poa languida | Drooping Speargrass | E | 2000 | |
| Vascular Plant | Polygonum puritanorum | Pondshore Knotweed | SC | 1934 | |
| Vascular Plant | Potamogeton vaseyi | A Pondweed | E | 1998 | |
| Vascular Plant | Prenanthes serpentaria | Lion's Foot | E | 1935 | |
| Vascular Plant | Ranunculus pensylvanicus | Bristly Buttercup | T | 1998 | |
| Vascular Plant | Rhododendron maximum | Great Laurel | T | 1999 | |
| Vascular Plant | Scheuchzeria palustris | Pod-Grass | E | 2001 | |
| Vascular Plant | Scirpus longii | Long's Bulrush | T | 2000 | |
| Vascular Plant | Scleria pauciflora var caroliniana | Papillose Nut-Sedge | E | 1989 | |
| Vascular Plant | Scleria triglomerata | Tall Nut-Sedge | E | 1989 | |
| Vascular Plant | Sclerolepis uniflora | Sclerolepis | E | 1996 | |
| Vascular Plant | Senna hebecarpa | Wild Senna | E | 1879 | |
| Vascular Plant | Sparganium natans | Small Bur-Reed | E | 1994 | |
| Vascular Plant | Sphenopholis nitida | Shining Wedgegrass | T | 1987 | |
| Vascular Plant | Spiranthes vernalis | Grass-Leaved Ladies'-Tresses | T | 1993 | |
| Vascular Plant | Trisetum triflorum ssp molle | Spiked False Oats | E | 1878 | |
| Vascular Plant | Vaccinium vitis-idaea ssp minus | Mountain Cranberry | E | 186- | |
| Vascular Plant | Veronicastrum virginicum | Culver's-Root | T | 1993 | |
| Vascular Plant | Viola adunca | Sand Violet | E | 2001 | |
| Vascular Plant | Waldsteinia fragarioides | Barren Strawberry | SC | 1833 |