Trilliums

a book by Frederick W. Case, Jr. and Roberta B. Case

Both field guide and gardener’s handbook, this book covers all 45 species of trilliums worldwide. The authors trekked all over North America to photograph the 38 American species in the wild.

Media reviews of this book:

“The book is a masterful description of all the species of trillium, their geographic distribution, habitat, and growing conditions ... It is a must-have book for the trillium enthusiast.”

—Chicagoland Gardening, May 2003

“A particularly informative and useful source of information. Wildflower enthusiasts and backyard gardeners will especially welcome the section dealing with trillium horticulture.”

—Donald S. Heintzelman, Northwestern Press, May 7, 2001

“After perusing this book, written by two addicted enthusiasts, you too will carry a torch for trilliums in the wild and in the garden.”

—C. Colston Burrell, Horticulture, March 2001

“Big, small, bright, subdued, sweetly-scented–and otherwise–lovely to look at–and occasionally otherwise–here are the Trilliums in all their diverse glory. Was ever a wildflower more exciting to chance upon while walking through a springtime woods?
Frederick Case, Jr., and Roberta Case have done a remarkable job in researching and writing this book and in assembling the photographs and mapping the boundaries of this widespread genus. Trilliums will be the definitive work on this genus for a long time to come.
Along with all the other pluses in Trilliums, the text is a treat to read. This is science at its best: understandable, interesting and useful. If you’re like me, you’ll find the only difficult part of owning this book is closing its covers and putting it down.”

—Charles E. Hardman, Executive Director, International Bulb Society

“Fred and Roberta Case have given us a thorough and enjoyable treatment of the genus Trillium based on over forty years of close observation and study in the wild and in the garden. This coupled with their knowledge of the literature, botanical, and horticultural, has resulted in clear explanations of the biological complexities and taxonomic confusion surrounding many of the species. The book is well-seasoned with personal experiences and opinionated observations making for easy and enjoyable reading. The comprehensive and well-organized species descriptions should serve as an example for horticultural monographs of other genera. In a clear, concise and standardized form they cover all information that the serious gardener might need to understand each species as it is presently conceived. I only wish this work had been available when I began my interest in the genus Trillium.”

—Richard W. Lighty, Ph.D., Director, Mt. Cuba Center for the Study of Piedmont Flora

Publishing details:

Hardcover, 286 pages, 6"x9", 75 color photos, 43 maps, 94 line drawings

©1997, Timber Press, ISBN 0-88192-374-5

An excerpt from this book:

“Threats to Wild Populations of Trilliums”

Picking Wild Trilliums.

It is popularly believed that picking a trillium even one time kills the plants. This is not true. Trilliums, like all green plants, obtain their food from the process of photosynthesis, the manufacture of carbohydrates from carbon dioxide and water using the energy of sunlighTrillium The organs of food-making are the green leaves, the light energy capturing and converting agent the green pigment chlorophyll. Naturally, anything which deprives the plant of its leaves injures Trillium.

Once picked, trilliums cannot produce another set of leaves until their cold dormancy requirement is satisfied, but trilliums have large, heavy rhizomes which store a considerable amount of food. If the plant picked is of reasonable health and size, it will appear the following season. If the rhizome is large and healthy enough, it may even bloom. There simply is no truth to the statement that picking a trillium once kills Trillium. However, our experience from our many lecture appearances and what we have written in the past indicates that some zealots ignore the facts and go right on believing the “facts” they want to believe.

Grazing by Wild or Domestic Animals.

It is true that repeated picking of the same plant, season after season before it can manufacture enough food to maintain itself, will eventually kill Trillium. A far greater threat to most wild Trillium populations than human picking is grazing by wild or domestic animals.

Repeated grazing, unlike the one-time picking of an individual plant, takes the same plants season after season, depleting their food reserves until they die. Maintaining wild deer herds at reasonable levels will save more trilliums than all the “education” not to pick. This is not to say that we advocate or approve of wanton picking, but there simply are not that many people out picking trilliums, and young children and the uninformed will pick a few no matter what people say.

Commercial Digging of Wild Trilliums.

Commercial collecting from wild trillium populations is not a good situation, as repeated collecting of a given area can deplete parental stocks or eliminate a rare species. Nursery propagation certainly is preferable and a better conservation practice.

Some propagation techniques are available, but present methods are slow, tedious, and commercially unprofitable. Some native plant dealers offer trillium rhizomes in quantity lots at wholesale and retail. Most do not state the origin of their plants; some call them “nursery stock.” To our knowledge, no true commercial quantity “propagation” takes place at the present time. The reader must realize that the term “nursery stock” may be misleading. In some states or other legal districts, wild-collected material can be kept in beds or rows for a specified period of time and then be classed as nursery stock.

If no laws covering the situation exist, dealers can call these plants what they may. Most trilliums offered today were collected in the wild. When taken legally from areas slated for development, we have no objection. In fact, we encourage legal rescue operations where the plants will otherwise be destroyed anyway. It is better that the gene pool be maintained in cultivation than totally destroyed. What we object to is illegal mass collecting from wild lands.

On the other hand, the amount of wild trillium material collected and sold or exported does not, so far as we can determine, approach the numbers given by zealous conservationists, conservation lobbyists, and those who seek to block export of all trilliums or to make a political issue of collecting them.

We do not condone mass commercial collecting from the wild. Threatened and endangered species of all wildlife should be protected by law, but we also believe there should be legal means by which properly qualified, trained botanists and horticulturists can bring into cultivation seed or selected, choice individuals of desired species, multiply them, and make them available to commercial sources so that anyone interested in these beautiful and worthy garden subjects can obtain them

Commercial Lumbering Techniques.

The type of commercial lumber harvesting utilized can have a big influence upon native wild plant populations. A new and, to many biologists, disturbing lumbering practice has appeared and is widely utilized in the southern United States and now in northern large private lumber company lands.

In this method, the area is clear-cut. All sizes of timber may be utilized: anything not of high quality is chipped for chipboard. No trees are left. Then, the land may be burned to kill brush and eventually sprayed with herbicide “to kill weed trees.” Finally, special trees, often hybrids or exotic species, are planted for a future timber harvest. This cut, slash, burn, and herbicide practice takes an enormous toll upon some native plants, alters the paths of natural succession, and may exclude the return of some native plants.

For the more delicate natives, lady’s slippers and other wild orchids, as for trilliums, the full effect on their populations is unknown. Any practice that totally alters a habitat usually takes out all individuals of a species dependent upon it, both adults and seedlings. With today’s technology, massive machinery, and aerial spraying of vast areas with powerful herbicides, we are concerned about the impact on trilliums and other native plant populations.

“Legal Protection of North American Trilliums”

In spite of all the dire talk and a few problem situations, most American Trillium species seem to be holding their own at present. Within the sometimes limited distributional ranges, if one enters the proper habitat, the species will be present, usually frequent, and, in the case of Trillium grandiflorum, Trillium erectum, Trillium sessile, Trillium recurvatum, and many others, locally abundant.

Many species thrive not only in mature forest, but also in second-growth forest and brushland, and some can invade fallow fields. Except for the species identified under the U.S. Endangered or Threatened Species Act, just a few Trillium species of very limited natural distribution may, at present, be in trouble. Only in urban areas, developments, some commercial lumber tracts, and areas of excessive human or deer population do most trilliums truly suffer and their numbers decline.

With continued human population growth and all its demands upon the land, we can expect that wildflower populations of all types will be increasingly stressed and damaged. We ought to set about now, before they become endangered, to protect our native plant treasures for the future.

About Frederick Case, Jr.

Frederick W. Case, Jr., and his late wife, Roberta, were partners in delightful plant adventures for some four decades. Hardy explorers, they trekked through swamps and woodlands to see and photograph each of the North American Trillium species in the wild.

Awards for Frederick Case, Jr.

• American Society of Plant Taxonomists - Peter H. Raven Scientific Outreach Award
• Arthur Hoyt Scott Garden and Horticultural Award

About Roberta Case

Roberta Case studied and grew trilliums for 45 years, and saw all 38 North American species in the wild. She resided in Saginaw, Michigan.

Ordering information:

Trilliums (Hardcover) (B-016)
Each $29.95
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Be sure to check out Digging Dog’s Trillium selections:

Trillium grandiflorum ‘Snowy White’

Trillium luteum