Hieracium longipilumTorr. ex Hook.

hairy hawkweed

WFO wfo-0000136100 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Hieracium longipilum, photographed by Thomas Koffel
fig. a Thomas Koffel, CC BY 4.0 / 2022-06-03 / obs. 204545955
Hieracium longipilum, photographed by Thomas Koffel
fig. b Thomas Koffel, CC BY 4.0 / obs. 188906635
Hieracium longipilum, photographed by Thomas Koffel
fig. c Thomas Koffel, CC BY 4.0 / obs. 155472930
Hieracium longipilum, photographed by Thomas Koffel
fig. d Thomas Koffel, CC BY 4.0 / obs. 129244859
Hieracium longipilum, photographed by Thomas Koffel
fig. e Thomas Koffel, CC BY 4.0 / obs. 127714353
Hieracium longipilum, photographed by Jason Swanson
fig. f Jason Swanson, CC0 1.0 / obs. 103312872
Hieracium longipilum, photographed by Alix Kosmala
fig. g Alix Kosmala, CC BY 4.0 / obs. 98953337
Hieracium longipilum, photographed by Thomas Koffel
fig. h Thomas Koffel, CC BY 4.0 / obs. 81448099

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

Native range 17 botanical countries

Regions where Hieracium longipilum is native: Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Michigan, Minnesota, Missouri, Nebraska, Ohio, Oklahoma, Ontario, Tennessee, Texas, Wisconsin ArkansasIllinoisIndianaIowaKansasKentuckyLouisianaMichiganMinnesotaMissouriNebraskaOhioOklahomaOntarioTennesseeTexasWisconsin
Native distribution of Hieracium longipilum, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows.
RegionTDWG codeContinent
Arkansas ARK NORTHERN AMERICA
Illinois ILL
Indiana INI
Iowa IOW
Kansas KAN
Kentucky KTY
Louisiana LOU
Michigan MIC
Minnesota MIN
Missouri MSO
Nebraska NEB
Ohio OHI
Oklahoma OKL
Ontario ONT
Tennessee TEN
Texas TEX
Wisconsin WIS

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Where it actually grows measured, from 460 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low -14.3 °C -9.5 °C 0.2 °C
Warmest month, mean daily high 27.2 °C 28.2 °C 33.4 °C
Annual rainfall 799 mm 921 mm 1,284 mm
Rainfall in the driest quarter 67 mm 101 mm 262 mm

It is found where winters bring hard frost. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 460 research-grade observations of Hieracium longipilum that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. USDA PLANTS Database. common name, checklist symbol HILO2. public domain. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.