New England Plant Conservation Program Conservation and Research Plan Asclepias purpurascens L. Purple milkweed Prepared by: Elizabeth J. Farnsworth New England Wild Flower Society Framingham, Massachusetts and Mario J. DiGregorio Horsley and Witten Environmental Consultants, Inc. Sandwich, Massachusetts For: New England Wild Flower Society 180 Hemenway Road Framingham, MA 01701 508/877-7630 e-mail:
[email protected] • website: www.newfs.org Approved, Regional Advisory Council, December 2001 SUMMARY Purple milkweed (Asclepias purpurascens L., Asclepiadaceae) is a rare but widely distributed species currently recorded from 25 eastern and mid-western states and Ontario, with historic records from another four states. All extant New England populations are restricted to Connecticut and Massachusetts; the species is considered historic in Rhode Island and New Hampshire. Only a total of 5 occurrences have been seen since 1980, of 82 collected before that time. Of these, only two have been observed recently and one remains to be confirmed as A. purpurascens. Both confirmed populations are small (with fewer than 30 plants) and appear precarious. The species is listed in the Flora Conservanda as Division I (Regionally Rare). Asclepias purpurascens is not federally listed and is a category G4G5 according to the Association for Biodiversity Information; thus, its status is not considered to be imperiled on a national or global scale. However, its population numbers are small throughout its range. Its precipitous recent decline in numbers in New England attests to the need for additional protective management to afford some level of habitat preservation and augmentation. Asclepias purpurascens is most commonly found along woodland edges and roadsides in mesic to well-drained soils that are not high in organic material.