Lawrence Gillett

Lawrence Gillett

Dicotyledoneae (Dicots)
Brassicaceae (Mustard Family)
State Protection
Federal Protection
Not Listed
State Conservation Status Rank
Global Conservation Status Rank


State Ranking Justification

There are 11 verified occurrences, several thousand plants.

Conservation and Management

Conservation Strategies and Management Practices




In New York, Purple Rock-cress has been collected primarily from open areas of calcareous rock, including marble cliffs, limestone woodlands, and calcareous pavement barrens, though elsewhere in its range it is not known as a calciphile (New York Natural Heritage Program 2011). Rocky slopes and sandy soil in prairies and open forests (FNA 2010). Sandy or gravelly clearings and borders of woods (especially aspen) and shores, rock outcrops and summits of "mountains." (Voss 1985). Sandy or rocky soil (Gleason and Cronquist 1991).

Associated Ecological Communities

  • Alvar pavement grassland (guide)
  • Calcareous cliff community* (guide)
  • Calcareous shoreline outcrop (guide)
  • Limestone woodland (guide)

Associated Species

  • Campanula rapunculoides (creeping bellflower)
  • Campanula rotundifolia (hare-bell)
  • Dryopteris marginalis (marginal wood fern)
  • Elymus hystrix
  • Geranium carolinianum var. sphaerospermum
  • Lonicera hirsuta (hairy honeysuckle)
  • Milium effusum
  • Ostrya virginiana (hop hornbeam, ironwood)
  • Packera paupercula (balsam groundsel)
  • Pellaea glabella
  • Poa compressa (flat-stemmed blue grass, Canada blue grass)
  • Polypodium virginianum (Virginian rock polypody, Virginian polypody)
  • Solidago arguta
  • Stellaria longipes
  • Thuidium abietinum
  • Thuja occidentalis (northern white cedar, arbor vitae)


New York State Distribution

Northern New York State, known from 3 topographic quads.

Identification Comments

Best Time to See

In New York flowering occurs from May to July, when the fruit begins to mature. The leaves persist as the fruit matures, into August. If found in July there may be both flowers and fruit present, facilitating identification.

  • Flowering
  • Fruiting

The time of year you would expect to find Purple Rock Cress flowering and fruiting in New York.

Purple Rock Cress Images


Purple Rock Cress
Boechera grahamii (Lehmann) Windham & Al-Shehbaz

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Dicotyledoneae (Dicots)
        • Order Capparales
          • Family Brassicaceae (Mustard Family)


  • Arabis x divaricarpa A. Nels. (pro sp.) [= Arabis drummondii x holboelii]
  • Arabis brachycarpa (Torrey & A. Gray) Britt.
  • Boechera divaricarpa (A. Nels.) A.& D. Löve
  • Boechera brachycarpa (Torr. & Gray) Dorn

Comments on the Classification

Recognition of Boechera grahamii as the oldest vaild name for apomictic hybrids between B.stricta and B.collinsii (=Arabis holboellii var. collinsii in Rollins, 1993) resolves serveral longstanding nomenclature issues.

Additional Resources


Gandhi, K.N. 1999. Nomenclatural novelties for the Western Hemisphere plants. II. Harvard papers in Botany 4: 295-299.

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.

Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.

New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.

Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research University of South Florida]. New York Flora Association, Albany, New York

Windham, M.D., and I.A. Al-Shehbaz. 2007b. New and noteworthy species of Boechera (Brassicaceae) III: Additional sexual diploids and apomictic hybrids. Harvard Papers in Botany 12(1): 235-257.

Zaremba, Robert E. 1991. Corrections to phenology list of April 9, 1991.


About This Guide

Information for this guide was last updated on: August 10, 2011

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Boechera grahamii. Available from: Accessed March 19, 2019.

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