TERATOLOGY IN TRILLIUM GRANDIFLORUM

HALL, MARION TRUFANT. (Butler U., Indianapolis, Ind.) Teratology in Trillium grandiflorum. Amer. Jour. Bot. 48(9): 803-811. Illus. 1961.-Attempts were made to determine the causes of persistent but seasonally variable abnormalities in both vegetative and floral organs of an assemblage of plants grouped under the name Trillium grandiflorum var. variegatum Smith. Comparative studies of vegetative and floral morphology between normal and abnormal plants are presented and illustrated. Normal shoots of the same rhizome vary but little from season to season. Abnormal shoots of the same rhizome vary markedly in some instances and very little in others from season to season. In the abnormal shoots, leaves and petals vary most, then stamens, ovaries, and sepals, in that order. In the populations observed, abnormal plants did not mature seed even though only a few specimens were seen which had no viable pollen. A comparative study of leaf and flower proteins of normal (var. grandiflorum) and abnormal (var. variegatum) plants was made. Electrophoretic analysis showed no virus but showed leaf protein abundant in the floral organs, particularly in the petals. It is suggested that the presence of these extra leaf proteins is sufficient to increase variability in the floral organs and in most cases to prevent the normal development of the sporophylls. CERTAIN variations in Trillium grandiflorum (Michx.) Salisb. may prove important for the investigation of several fundamental biological problems. Some of these variations have been studied for several years, and I shall present some preliminary observations concerning their significance. Occasionally, in natural populations of Trillium grandiflorum there are found large numbers of abnormal plants which were lumped together and named Trillium grandiflorum var. variegatum Smith. Since Smith (1879) noted these unusual forms, they have been reported again and again, particularly from Michigan, southwestern Ontario, the Don Valley, Ontario, and the vicinity of Buffalo and Syracuse, New York. Numerous reports of these abnormal forms made prior to 1917 have been summarized by Gates (1917); later reports bv Farwell (1919, 1921, 1928), P. Louis-Marie (1940a-d), P. Louis-Marie and R. Giroux (1950) indicate the variety of freaks and their persistence in the habitats where they are found. The evidence suggests that these freaks are mostly sterile and should be considered a teratological assemblage without nomenclatural status. The aspect of plants of Trillium grandiflorum (Fig 2-8), both normal and abnormal, is shown for a single stand in northeastern Oakland County, Michigan. For further comparison of the character1 Received for publication March 5, 1961. This research was supported by funds from the Cranbrook Institute of Science, Bloomfield Hills, Michigan. The protein studies were done with the aid and advice of Barry Commoner, Milton Zucker, and Sidney Rodenberg at the virus laboratories of the Henry Shaw School of Botany, Washington University of St. Louis. The author exuresses his gratitude to these and to Robert T. Hatt and Stephen M. Stackpole for photography, to Walter P. Nickell, Dale J. Hagenah, and Paul W. Thompson for field assistance. The author is grateful to the University of Michigan Botanical Garden for space and care of plants. istics of normal and abnormal Trillium grandiflorum from this single stand see Table 1. Variability is greatest in the petals particularly in shape and in the relative amount of green tissue present. Petals with more green tissue become more leaf-like in general morphology. Phyllody among the stamens drastically cuts down the amount of pollen, but in many flowers there is a small amount of apparently good pollen. Phyllody in the ovary results in sterility. In appearance, these abnormal plants suggest the condition found in Parrot-tulips where the abnormal behavior in morphology is the result of virus transmission in propagules. For in the Parrottulips the activity of the virus is sufficient to cause "breaking" in color to produce marked streaking, to cause fringing of petal margins, and elongation of plant organs producing a more lax habit. Similar variegation and streaking occur in tobacco and petunia where viruses have determinative effects. The distribution of the freaks suggested the possibility of virus infection. In southern Michigan, they occur only in woods of the northern type, i.e., in cold woods, maple, beech, white pine, hemlock, yew, yellow birch. They occur again in similar habitats far to the north, e.g., in Leelanau County, Michigan. For this reason, it was suspected that the development of freak patterns may be the result of virus production on a differential basis, since it is well known that cool temperatures and in some cases restricted light (northern climates and shady habitats [Bawden, 1950]) favor the production of virus lesions in infected organisms, apparently creating competition in protein synthesis which restricts the production of normal protein and results in an upset in the normal metabolism of the organism. It was thought that Trillium grandiflorum normals and abnormals should be studied and com-