Quercus marilandica(L.) Münchh.

blackjack oak

WFO wfo-0000291931 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h

Quercus marilandica, photographed by Micki Colbeck
fig. a Micki Colbeck, CC BY 4.0 / 2022-06-09 / obs. 204724827
Quercus marilandica, photographed by Judy Gallagher
fig. b Judy Gallagher, CC BY-SA 4.0 / obs. 199092150
Quercus marilandica, photographed by Jeff Clark
fig. c Jeff Clark, CC BY 4.0 / obs. 199518094
Quercus marilandica, photographed by Jeff Clark
fig. d Jeff Clark, CC BY 4.0 / obs. 199517218
Quercus marilandica, photographed by Joseph Aubert
fig. e Joseph Aubert, CC BY 4.0 / obs. 203768648
Quercus marilandica, photographed by Jeff Clark
fig. f Jeff Clark, CC BY 4.0 / obs. 205619342
Quercus marilandica, photographed by saltyhiker
fig. g saltyhiker, CC BY 4.0 / obs. 202555648
Quercus marilandica, photographed by Samuel A Schmid, PhD, PWS
fig. h Samuel A Schmid, PhD, PWS, CC BY 4.0 / obs. 205634834

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.

Confused withby our own model

These are not lookalikes we guessed at. Each one is a species our identification model genuinely mistook for this plant, and how many times. The error rate is published.

Flowering n = 77 observations

Peak flowering in Apr, from 77 community-annotated observations worldwide. This is a global aggregate, not a forecast for your garden: the same species flowers on different dates in different hemispheres, and citizen-science records cluster near cities, at weekends, and in spring. Where a species has fewer than 30 annotated records we do not draw this chart at all.

Also published as 20 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Quercus cuneata Wangenh.
  • Quercus dilatata Raf.
  • Quercus ferruginea F.Michx.
  • Quercus marilandica f. aequilobata Trel.
  • Quercus marilandica f. cuneata (Wangenh.) Trel.
  • Quercus marilandica f. incisa Trel.
  • Quercus marilandica f. integrifolia (Marshall) Trel.
  • Quercus marilandica f. obovata Trel.
  • Quercus marilandica f. paucidentata Trel.
  • Quercus marilandica f. quinqueloba Trel.
  • Quercus marilandica f. sublyrata Trel.
  • Quercus marilandica f. subquinqueloba Trel.
  • Quercus marilandica f. subtypica Trel.
  • Quercus marilandica f. truncata Trel.
  • Quercus marilandica var. ashei Sudw.
  • Quercus neoashei Bush
  • Quercus nigra var. integrifolia Marshall
  • Quercus nigra var. marilandica L.
  • Quercus nigra var. quinqueloba A.DC.
  • Quercus nobilis Hort.Ottoland. ex Mast.

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.

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