Rare, Threatened and Endangered Plant Fact Sheets

Sandplain Gerardia

[Sandplain Gerardia] 
[Sandplain Gerardia - detail]​​

In 1950, a botanist discovered and collected a specimen of an extremely rare wildflower at Soldiers Delight Natural Environmental Area in Baltimore County. For decades the plant's identity was not known. Finally, in 1984, the original specimen from the site was reexamined and determined to be sandplain gerardia (Agalinis acuta), a relative of the snapdragon known from only three other states in the country. Since this recent verification, Maryland biologists have been working to protect this precious flower from extinction.

Natural History

Sandplain gerardia is known to occur at sites on Cape Cod, Massachusetts; Long Island, New York; and in Rhode Island and Maryland. Its historical range included the coastal plain of Connecticut, where the wildflower is no longer found.

Sandplain gerardia, an annual, reaches a height of four to eight inches. Its long, thin leaves grow sparsely along its light green stem and branches. Appearing in late August to early September, its beautiful pink or purple flowers bloom for only a day. Sandplain gerardia grows in dry, sandy open areas of the coastal plain. It is primarily found in acidic, low-nutrient soils, where many other plants that might compete for sunlight, water, or growing space cannot survive. In Maryland, sandplain gerardia grows in a rare prairie-like habitat called a serpentine barren, where most vegetation is sparse. 

Very little is known about the ecology of sandplain gerardia. One aspect that puzzles biologists is the role of parasitism in the plant's life history. Other gerardia species are parasites, living off the nutrients of other plants while contributing nothing to their hosts in return. Biologists have not yet determined which plants may serve as hosts to the species, or if sandplain gerardia depends on parasitism at all. The answers will be significant for the plan's future, for the absence of a host species may be contributing to sandplain gerardia's decline.

Another puzzling component of the species' ecology is how disturbance to seeds and soil may aid in the plant's survival. Historically, sandplain gerardia's habitat was subjected to periodic natural and human-caused disturbances such as livestock grazing, drought, and fire. These disturbances may have been a key factor in the plant's seed germination. Presently, nearly every site containing a healthy population of the species receives some form of disturbance, including sporadic fires, mowing, herbicide spraying, and use of nearby horse trails.

How Is Sandplain Gerardia Endangered?

Perhaps the most imminent threat to sandplain gerardia is loss of habitat. Along the Eastern Seaboard, the coastal plain has been intensively developed for housing, agriculture, industry, and commercial purposes. Maryland's only other known population of sandplain gerardia was destroyed by urbanization and highway construction. Guided by historic records, botanists hoping to rediscover old populations of the species have arrived at given locations only to find residential developments, highways, and marinas in their place.

The population numbers of sandplain gerardia sometimes vary widely from year to year. Among annuals, some population fluctuation is natural. However, sandplain gerardia's recent rangewide decline has been greater than biologists expected, with several sites disappearing completely. When any remaining population declines in numbers, there is an increased threat that minor catastrophes could destroy the entire population. In addition, with fewer and fewer plants from which to maintain the genetic diversity of populations, the general health and "vigor," or vitality, of sandplain gerardia populations may be at risk. Sustaining high numbers of individual populations remains a primary concern of biologists working on the endangered plant.

Even in undeveloped areas, the lack of grazing animals and of natural fires has allowed the growth of shrubs and trees, which block out vital sunlight. Some biologists also believe the species' decline may be at least partially due to lack of effective pollination. In recent decades, insecticide use has damaged many insect populations, and may well have affected the pollinators of sandplain gerardia.

Actions to Help Sandplain Gerardia Survive

The U.S. Fish and Wildlife Service (USFWS) officially listed sandplain gerardia as an Endangered Species in 1988. This listing recognizes that the plant may become extinct in the near future, recommends actions for the species' protection, and authorizes the creation of a Recovery Plan. This Recovery Plan outlines specific goals relating to research on the species' biology and habitat, to monitoring existing populations, to cultivating the plant, and to protecting its habitat. If these goals are achieved, sandplain gerardia may one day no longer be in danger of extinction.

Sandplain gerardia was listed in 1987 on the State of Maryland's list of Threatened and Endangered Species. Maryland's single known population grows on a site that has been protected for close to twenty years as a state Natural Environmental Area. Most populations in other states grow on private lands, however, and could be threatened by habitat destruction in the near future. Conservation groups and government agencies plan to work with landowners willing to help safeguard the wildflower.

Since experts believe that habitat disturbance may play a key role in sandplain gerardia's survival, protection of the species must involve active management of its habitat. To determine the precise nature and timing of this disturbance, the Wildlife and Heritage Service of the Maryland Department of Natural Resources is conducting research and experiments at Soldiers Delight Natural Environmental Area. The information from this research will provide valuable insight for future management. Conservation groups in Massachusetts, Rhode Island, and New York are also sponsoring studies of sandplain gerardia in both the field and laboratory, hoping to uncover vital clues about the plant's ecological needs. Ecologists are also working to develop optimal methods for maintaining the open grasslands at Soldiers Delight for the benefit of the endangered wildflower.

For more information about Sandplain Gerardia, and other rare species, please contact:

Maryland Department of Natural Resources
Wildlife and Heritage Service
Tawes State Office Building, E-1,
Annapolis, MD 21401
Phone (410) 260-8540
Toll-free in Maryland: 1-877-620-8DNR, Ext. 8540

Acknowledgments: Written by Johanna Thomas with the assistance
of other Wildlife and Heritage staff members.
Illustration, layout, and design by Josephine Thoms, DNR Land Planning Services.