Quercus

Tennessee › Apiaceae

Cow-parsnip

Heracleum maximum
Also known as

American Hogweed; Cow Parsnip; Masterwort

Listed in Tennessee’s rare-plant reference. Use nursery-propagated plants; conservation status is separate from this ecological score.

28
Good
Tennessee · provisional Quercus Score

Calculated with the same rules as North Carolina, using Tennessee host-range and conservation-rank inputs. Native-status evidence is shown separately.

Tennessee scoring method and limits

Insect resources, birds and habitat

Caterpillars3 recorded species on the genus
Host genera of native Lepidoptera recorded in Tennessee; host association and range overlap, not confirmed local feeding.
Bees5 recorded species on the genus
Southeastern North America
Specialist bees0 recorded species on the genus
Eastern North America
Birds0 recorded species on the genus
North America
StructureForb/herb

Baseline 32; additional insect credit +4. Rarity adjustment -8 using the NC rule (unranked: −5; final score floor: 5). Missing records do not establish zero ecological use.

Native to Tennessee (state-specific source). Tennessee yard-fit calculations are not available yet.

Also available: North Carolina assessment. Both assessments use the same scoring rules with the evidence shown for each state.

Recorded in your county?

Choose a county to check the available records.

County occurrence is not proof of native range or yard suitability. A missing record does not establish absence.

Tennessee statusNative to Tennessee (state-specific source)
Source conservation rankS2
Recorded in Tennessee8 counties in the atlas snapshot

Growing conditions

Full sun to shade, moderately wet to medium moisture level, adapted to a wide range of soils including clay, moderately acid to neutral pH. 6-8 feet height, blooms spring into summer, white flowers, spreads rapidly by seed.

Native Region: Only in Stewart, Polk, Blount, Cocke, Greene, Washington, and Unicoi counties UT Smart Yards source

Native-status evidence

Combined TN–KY atlas flag: Y. A regional flag alone does not settle Tennessee native status.

Combined-source assessment

Native to Tennessee (state-specific source)

A TN-specific UT native-guide page or an exact entry in the Tennessee rare-plant list supports a direct source claim. Otherwise, TN occurrence plus an atlas native flag and exact-name native evidence from NC flora or USDA L48 supports a provisional state inference. No one regional claim or occurrence alone establishes TN nativity; NC and L48 claims retain their actual scopes.

UT Tennessee Smart Yards native-plant guide: native (TN). Native Region: Only in Stewart, Polk, Blount, Cocke, Greene, Washington, and Unicoi counties

Tennessee Natural Heritage rare-plant list (2025): native (TN). Heracleum maximum Cow-parsnip MOIST WOODS AND FLOODPLAINS FL: MAY-JUL, FR: JUL-AUG WR, RV, BR S S2 G5 Heteranthera limosa Blue Mud-plantain MUD FLATS FL: JUN-SEPT, FR: JUN-SEPT WR, CB, CP, MF T S1S2 G5

NC vascular flora: native (NC).

USDA PLANTS: native (L48). AK:N CAN:N L48:N SPM:N

TN–KY Plant Atlas: native (TN–KY).

Sources

Machine-readable: plant evidence.

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