This species and the common tall blue lettuce, Lactuca biennis, are the only species of wild lettuce with fruit hairs (pappus) in double rings. Lactuca means milk in Latin and refers to the milky sap of this genus (Fernald 1950).
There is only one existing population with less than 50 plants. There are records from 1851 and 1924 that remain to be checked to see if they still exist.
More survey work is needed to understand short-term trends.
This plant has always been very rare in New York and continues to exist at low levels.
One population is near a path and may be threatened by improper path management or direct trampling.
Plant should be monitored occasionally to see if they are being directly affected by park visitation.
Herbarium work is needed to determine if all specimens are correctly identified. Propagation work should be done to see if the present population could be augmented. We would also like to know what limits its growth in New York.
The plants occur in oak-hickory forest on rich, moist soil. A historical specimen was from hilly, rich woods (New York Natural Heritage Program 2012). Rich woods, thickets and openings (Fernald 1970). Thickets, woods, and moist, open places (Gleason & Cronquist 1991).
This wildflower was known from the Hudson Valley from Dutchess County to the Bronx and also in Nassau County on Long Island. There is an unsubstantiated report from Chemung County. It is currently known only in the Bronx.
This herb is common in the eastern United States east of the short grass prairie. It is less common in the northern tier of states from New York to Minnesota and in the provinces of Manitoba and Ontario.
This plant is a tall annual or perennial wildflower that grows up to 2 meters tall. The leaf blades only have hairs along the main veins beneath and they vary from elliptic with a few teeth to very lobed or even these few leaflets at the base. The 11-17 (sometimes up to 25) flowers are bluish, or white in a large open inflorescence. The pappus is bright white. The achenes are 4-6 mm long, gray-black and mottled and several-nerved on each face.. The outer fruits are often distinctly thick-beaked, the inner are beakless.
Distinguishing characteristics: leaves lyrate or runcinate-pinnatifid; flowers bluish, or white; inflorescence ample, open-paniculiform; pappus bright white; achenes gray-black or fuscous, mottled, the outer often distinctly thick-beaked, the inner beakless. Best life stage for ID: in fruit. Characteristics needed to ID: mature achenes.
The best time to identify this species is when it is in fruit.
Lactuca biennis has a light brown pappus and elongate, narrowly paniculiform inflorescence.
The plants flower in July and August and mature fruits develop August through mid-October.
The time of year you would expect to find False Lettuce flowering and fruiting in New York.
Lactuca floridana (L.) Gaertn.
Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.
Flora of North America Editorial Committee. 2006. Flora of North America North of Mexico. Vol. 19. Magnoliophyta: Asteridae, Part 6: Asteraceae, part 1. Oxford Univ. Press, New York. xxiv + 579 pp.
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.
Mitchell, Richard S. and Gordon C. Tucker. 1997. Revised Checklist of New York State Plants. Contributions to a Flora of New York State. Checklist IV. Bulletin No. 490. New York State Museum. Albany, NY. 400 pp.
New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.
New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.
Reschke, Carol. 1990. Ecological communities of New York State. New York Natural Heritage Program, New York State Department of Environmental Conservation. Latham, NY. 96 pp. plus xi.
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
This guide was authored by: Stephen M. Young
Information for this guide was last updated on: September 20, 2012
Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Lactuca floridana. Available from: https://guides.nynhp.org/false-lettuce/. Accessed September 23, 2019.