isoflor

English

Etymology

iso- + clipping of flora. The Eocene fossil sense was first employed by Chaney in 1940 (see quotations).

Noun

isoflor (plural isoflors)

1. An isoline on a map that connects areas where a given number of plant taxa can be found, particularly species within a certain genus or family.
   • 1985, Nigel Maxted, An Ecogeographical Study of Vicia Subgenus Vicia, page 93:

     Isoflor maps do not show actual species distributions, but each line is a contour delimiting a greater or lesser concentration of species. The species distributions for each species is plotted onto one sectional map, then contours are drawn around areas of similar species concentration. The isoflor maps are intended to indicate patterns of distribution concentration, rather than actual distributional patterns.

2. An isoline on a map that connects sites with similar Eocene fossil floras.
   • 1940, Ralph W. Chaney, “Bearing of Forests on the Theory of Continental Drift”, in The Scientific Monthly, volume 51, number 6, pages 489–499:

     But by drawing lines known as isoflors we may approximate the positions of Eocene isotherms. These lines connect floras of the same general composition, which are assumed to indicate, as do similar floras to-day, essentially the same climatic background. The isoflor connecting the localities where subtropical floras have been recorded, as shown by Fig. 9, swings up the west coast of Europe into England, then turns southward into France and trends in a southeasterly direction, with a bulge north over the Black Sea […]