There are 11 verified occurrences, several thousand plants.
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).
Northern New York State, known from 3 topographic quads.
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.
The time of year you would expect to find Graham's Rock Cress flowering and fruiting in New York.
Graham's Rock Cress
Boechera grahamii (Lehmann) Windham & Al-Shehbaz
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.
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. 2020. 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 http://www.fccdr.usf.edu/. University of South Florida http://www.usf.edu/]. New York Flora Association http://newyork.plantatlas.usf.edu/, 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.
Information for this guide was last updated on: August 10, 2011
Please cite this page as:
New York Natural Heritage Program. 2020. Online Conservation Guide for Boechera grahamii. Available from: https://guides.nynhp.org/purple-rock-cress/. Accessed September 26, 2020.