V‘ 0"‘9m‘vfuw“o‘\-‘0 «~“‘-l “h“‘. “n “~ 7,-‘o g. Q'- ‘\.'-,'1 POLLINATION BIOLOGY IN SEVEN TAXA OF MICHIGAN DRCHIDACEAE AND A STUDY OF CYPRIPEDIUM CALCEDLUS IN MICHIGAN BASED ON LIVING PLANTS AND HERBARIUM SPECIMENS Thesis for the Degree of M. S. MICHIGAN STATE UNIVERSITY CATHEY IO NEWHOUSE 1976 III III IIIIIIIIIIIIIIIIIIILIIII 3 1293 ABSTRACT POLLINATION BIOLOGY IN SEVEN TAXA OF MICHIGAN ORCHIDACEAE AND A STUDY OF CYPRIPEDIUM CALCEOLUS IN MICHIGAN BASED ON LIVING PLANTS AND HERBARIUM SPECIMENS By Cathey Jo Newhouse Seven taxa of Michigan Orchidaceae (Pogonia ophioglossides, Calopogon tuberosus, Habenaria blephariglottis, Cypripedium acaule, Cypripedium reginae, Cypripedium calceolus var. pubescens, and Cypripedium calceolus var. parviflorum) were studied to determine the normal means of reproduction, the self-compatibility, and the polli- nating agent. With the exception of Pogonia_9phioglossoides, all species were found to be normally cross-pollinated, but to have no self—sterility barriers. Self-pollination is ruled out by mechanical factors preventing the transfer of pollen to the stigma. In addition, six of the species were found to be obviously capable of vegatative reproduction. Pogonia gphioglossoides exhibited a pattern indicating either some form of cleistogamy or a form of apomixis. Specific polli- nating agents are given where observed. A study was also carried out of the two varieties of Cypripedium calceolus in Michigan (var. pubescens and var. parviflorum) based on living plants and herbarium material. A classical Cathey Jo Newhouse morphological analysis was used along with a statistical analysis of characters. In the area of study, at least, these two taxa were found to be behaving very much like two distinct species. POLLINATION BIOLOGY IN SEVEN TAXA OF MICHIGAN ORCHIDACEAE AND A STUDY OF CYPRIPEDIUM CALCEOLUS IN MICHIGAN BASED ON LIVING PLANTS AND HERBARIUM SPECIMENS By Cathey Jo Newhouse A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Botany & Plant Pathology 1976 ACKNOWLEDGEMENTS I am very appreciative of the financial support given me by the National Science Foundation in the form of a graduate fellowship and by the Department of Botany and Plant Pathology at Michigan State University in the form of teaching assistantships. I am especially grateful to Dr. John Beaman for the encour- agement and advice during the two years of my graduate study and during my undergraduate years. The help he has given me is very deeply appreciated. Thanks go also to Dr. R.L. Fischer who was kind enough to make determinations-of the insects that I collected during this study; to Mr. Frederick Case, Jr. and Dr. Warren P. Stoutamire, both of whom gave me information on additional localities for the species I studied; and to Dr. Peter Murphy and Dr. Ralph Taggart, the other members of my graduate committee who gave much-appreciated suggestions and helpful advice. Also, I am very grateful to Dr. Henry Imshaug who read the manuscript and gave helpful comments and valuable time during the com— pletion of this degree program. To Mr. James O'Conner of Rogers City, Michigan, I would like to extend thanks for showing me localities for three taxa I studied in Presque Isle County. Mr. Fred Patterson, who generously provided the illustrations, also deserves thanks. ii I would especially like to thank my parents for support, both moral and financial, during this study. Their help has meant a great deal to me. Finally, very special thanks go to my husband, Chris, for his ideas and help in my field studies, and especially for his continued understanding and encouragement. iii TABLE OF CONTENTS Page General Introduction . 1 Part I. Pollination Biology in Seven Taxa in Michigan Orchidaceae . 2 Introduction . 2 Calopogon tuberosus (L.) BSP. 2 Pogonia ophioglossoides (L.) Ker. 6 Habenaria blephariglottis (Willd.) Hook . 11 Cypripedium . 15 Cripedium acaule Ait. 21 Cypripedium reginae Walt. 21 Cypripedium calceolus (var. pubescens (Willd.) Correll and var. parviflorum)(Salisb.) Fernald . 23 Methods and Materials . 32 Results . 37 Calopogon tuberosus (L. ) BSP. 37 Pog_nia ophioglossoides (L. ) Ker. 33 Habenaria blephariglottis (Willd. ) Hook . 39 Cypripedium acaule Ait. 40 Cypripedium reginae Walt. 41 Cypripedium calceolus var. pubescens (Willd.) Correll . 42 Cypripedium calceolus var. parviflorum (Salisb. ) Fernald . 43 Discussion . 44 Calopogon tuberosus (L.) BSP. 44 Pogonia ophioglossoides (L.) Ker. 48 Habenaria blephariglottis (Willd.) Hook . 50 Cypripedium acaule Ait. 52 Cypripedium reginae Walt. 54 Cypripedium calceolus (var. pubescens (Willd.) Correll and var. parviflorum) (Salisb. ) _ Fernald . 56 Conclusions . 58 iv Page Part II. A Study of_§ypripedium calceolus in Michigan Based on Living Plants and Herbarium Specimens . 59 Introduction . 59 Classical or Morphological Approach . 65 Statistical Approach . 73 Conclusions . 92 Bibliography . 95 LIST OF TABLES Table Page Probabilities with respect to F1 and F2 for the measurement intervals of variable 1 (lip length) . 77 Probabilities with respect to F1 and F2 for the measurement intervals of variable 2 (lip height) . - 77 Probabilities with respect to F1 and F2 for the measurement intervals of variable 3 (lip width) . - 78 Probabilities with respect to F1 and F2 for the measurement intervals of variable 4 (lateral petal length) I O O I O O O O O O O I O O O O O O O O O 78 Probabilities with respect to F1 and F2 for the measurement intervals of variable 5 (lateral petal Width) 0 O 0 I O O O O O O O O O O O O O O O O O O O O 79 Probabilities with respect to F1 and F2 for the measurement intervals of variable 6 (number of spirals in lateral petals) . 79 Probabilities with respect to F1 and F2 for the measurement intervals of variable 7 (dorsal sepal length) 0 O O O O O O O O O O O O O O O O O O O O O O 80 Probabilities with respect to F1 and F2 for the measurement intervals of variable 8 (dorsal petal Width) 0 O O O O O O I O O O O O O O I O O O O O O I I 8O Probabilities with respect to F1 and F2 for the measurement intervals of variable 9 (number of leaves) 81 10 Probabilities with respect to F1 and F2 for the measurement intervals of variable 10 (pubescence on flower) . 81 ll Probabilities with respect to F1 and F2 for the measurement intervals of variable 11 (pubescence on leaves) . 82 12 Probabilities with respect to F1 and F2 for the measurement intervals of variable 12 (pubescence on stem) . 82 vi Table Page l3 Probabilities with respect to F1 and F2 for the measurement intervals of variable 13 (soil moisture) . 83 14 Probabilities with respect to F1 and F2 for the measurement intervals of variable 14 (degree of shade) 83 15 Probabilities with respect to F1 and F2 for the measurement intervals fo variable 15 (color of markings inside lip) . O . O O O O O O 84 . 16 Probabilities with respect to F1 and F2 for the measurement intervals of variable 16 (color of lateral .petals) . 84 17 Probabilities with respect to F1 and F2 for the measurement intervals of variable 17 (fragrance) . 85 18 Probabilities with respect to F1 and F2 for the measurement intervals of variable 18 (ratio of length' to width of dorsal sepal) . 85 19 Probabilities with respect to F1 and F2 for the measurement intervals of variable 19 (ratio of length to width of top leaf) . 86 20 Exemplary variable measurements and probabilities, combined probabilities, and hypothesis chosen on the basis of the combined probabilities for 10 observations 88 21 A comparison of absolute combined probability dif- ferences when based on all 19 characters and when based on the nine characters that are likely to be measurable on herbarium specimens . 9O vii LIST OF FIGURES Figure Page 1 Calopogon tuberosus . 4 2 Pogonia ophioglossoides . 8 3 Cypripedium, longitudinal section of flower . 22 4 Insect visitors to flowers studied . 26 5 Apparatus used in insect exclusion experiments . 33 6 Map of Michigan showing location of study areas . 36 7 A comparison of author differences in Cypripedium calceolus characters . 66 8 The 26 variables measured in the Cypripedium calceolus study . 69 9 Observed ranges, means, and standard deviations for each of the 19 variables used in the Cypripedium calceolus study . 72 viii GENERAL INTRODUCTION Pursuing dual interests in the Orchidaceae and in pollination biology, I undertook a study of various aspects of reproductive biology in seven groups of Michigan orchids. In this study I attempted to determine the normal means of reproduction, the self- compatibility, and the pollinating agent for each taxon. I further studied Cypripedium calceolus in Michigan in order to find a method to readily identify infraspecific taxa on the basis of either living or herbarium material. PART I. POLLINATION BIOLOGY IN SEVEN TAXA OF MICHIGAN ORCHIDACEAE Introduction Pollination biology of terrestrial orchids has long been debated 'and discussed, but relatively few people have studied this subject in detail. During the latter part of the nineteenth century several researchers made observations on different aspects of the pollination of some members of the Orchidaceae, but since that time, reports of such studies have been relatively few. Calopogon tuberosus (L.) BSP. Calopogon tuberosus (and not Calopogon pulchellus) is the correct name for this taxon (c.f. MacKenzie, 1935; Voss, 1966). Calopogon flowers have long been a source of interest to naturalists. Because it is a widely distributed genus and is frequently encountered in bogs and marshes, it has been studied perhaps more than any other single group of terrestrial orchids in North America. Al- _though it is not one of the groups studied by Charles Darwin (1862, 1877) or other early European investigators, it has been observed and studied by almost every one of the early researchers in North America.