BIOSYSTEMATIC STUDIES IN THE GENUS PIPERIA (ORCHIDACEAE) by James D. Ackerman A Thesis Presented to The Faculty of Humboldt State University In Partial Fulfillment of the Requirements for the Degree Master of Arts June, 1976 BIOSYSTEMATIC STUDIES IN THE GENUS PIPERIA (ORCHIDACEAE) by James D. Ackerman Approved by the Master's Thesis Committee Chairman Approved by the Graduate Dean ACKNOWLEDGEMENTS Dennis E. Anderson's patience, guidance and support throughout this project is most gratefully acknowledged. I appreciate members of my committee, Richard L. Hurley, Robert A. Rasmussen, and Farris R. Meredith for lively discussions and reading the manuscript. I also thank William V. Allen for access to laboratory equipment, Jerry A. Powell for identifying the moths, Arlee M. Montalvo for aid through various aspects of this work, and the curators and staffs of those herbaria that provided specimens for study. TABLE OF CONTENTS Page Acknowledgements Introduction 1 Taxonomic History 7 Materials and Methods 12 Results and Discussion 22 Osmophors 22 Chromosomes 22 Chromatography 27 Interfertility 37 Field Studies 46 Morphology 49 Character analysis 49 Taxonomic concepts 60 Summary 66 Distribution 68 Conclusions 74 Taxonomy 79 Keys to Piperia taxa 79 Piperia 81 Piperia elegans 82 Piperia unalascensis 86 Piperia maritima 89 Piperia maritima var. multiflora 92 Piperia transversa 94 Piperia michaeli 96 iii Table of Contents. Continued. Page Appendices 98 Literature Cited 107 INTRODUCTION Piperia Rydberg is a polymorphic genus and presents complex taxonomic and nomenclatural problems. Variability exists in nearly all morphological aspects including the usually conservative features of the column. Many species have been proposed based on plants showing limited ranges of continuous characters; this has resulted in considerable confusion. Piperia has been split into as many as nine species by Rydberg (1901b, and in Abrams, 1922) whereas others have consolidated all forms into one (Correll, 1943 and 1950; Calder and Taylor, 1968). Occasionally two different forms grow together without intermixing. Evidence such as this casts doubt upon the validity of consolidating all forms under one or a few taxonomic categories. In contrast, upon examining herbarium specimens, most of these forms, at least superficially, appear to intergrade with one another. Obviously, a reevaluation and enhancement of characters used to delineate piperias is needed. A combination of classical morphology, biochemistry, and reproductive biology is the basis of this study. The distribution of Piperia is largely western: from Baja California to the Aleutian Islands of Alaska and throughout much of British Columbia and the Western States; however, there are disjunct populations in South Dakota, around the Great Lakes, and in the vicinity of the St. Lawrence Seaway. 2 Piperias shy from boggy habitats. Except for Piperia maritima Rydberg, a species often found on open coastal bluffs, they prefer relatively dry coniferous forest and in their southernmost outposts, chaparral. In early spring, mature piperias produce 2-4 basal leaves, which wither before or during anthesis. In Southern California, piperias may flower as early as April but northward they do not flower until early to late summer. The genus Piperia is usually included in either Platanthera L. C. Rich. or Habenaria Willd. According to Dressler's (1974) classification of the Orchidaceae, Piperia, although not accepted by him, belongs in the tribe Orchideae. Recently, American orchidologists have reconsidered the generic concept of Habenaria. This reevaluation resulted in recognition of several segregate genera, including Piperia. Traditionally, European botanists have recognized many segregate genera (at least seven) whose defining characteristics are rather nebulous. The unifying features of one genus often intergrade with another (see Lindley, 1830-1840). At the other extreme, American orchidologists have allowed for a high degree of variability. Ames (1910) and, later, Correll (1943 and 1950), in their treatments of North American habenarias, readily accept a polymorphic concept of Habenaria, which has been used widely in floristic treatments of North America. Rydberg (1901a and 1901b) took exception and followed European botanists by retaining a restricted 3 concept of the genus and recognizing many segregate genera. A compromising approach, though not without error, was given by Schlecter (1927) but was not widely accepted. Dressler and Dodson (1960) suggested reassessment of the genus for they were dissatisfied with the polarity in concepts of Habenaria. Love and Simon (1968) argued for retaining 14 segregate genera, an approach as extreme as that of Ames and Correll. Since then, intermediate schemes have been suggested by Luer (1975) and Dressler (1974). From North America, these authors recognize Platanthera, Coeloglossum Hartman (monotypic), Habenaria, and Piperia (Luer only) as distinct genera. The true habenarias (Ames' section Euhabenaria) grow only in the tropical and subtropical regions (Rydberg, 1901b; Ames, 1910; Schlecter, 1927; Stoutamire, 1974; Luer, 1972 and 1975). Table 1 compares various generic treatments of the Habenaria complex in North America, north of Mexico. The validity of generic status for Piperia is briefly discussed by Luer (1975) and some of his arguments reflect those of Rydberg (1901b). They suggest, in part, that recognition of Piperia is justified by the general acceptance of similar taxonomic treatments of related problematic groups. The addition of several more diagnostic features than mentioned by Luer and Rydberg presents a convincing argument for retention of generic status. The most noteworthy features are: usually two ovoid tubers; Table 1. Selected generic treatments of the Habenaria complex in North America north of Mexico. Ames (1910) & Schlecter Dressier Luer (1975) Britton & Brown Correll (1950) (1927) (1974) (1913; follows Rydberg) Habenaria Habenaria Habenaria Habenaria Habenaria Platanthera Platanthera Platanthera ---- Lysias Lysiella 4 Blephariglottis Limnorchis Piperia Piperia Gymnadenia Platanthera Gymnadeniopsis Denslovia* Platanthera Perularia Coeloglossum Coeloglossum Coeloglossum * Not in Britton and Brown (1913) but later provided by Rydberg (1931). 5 basal leaves withering before or during anthesis; perianth parts one-nerved; two viscidia close together above the orifice to the spur; anther cells parallel and adjacent; stigma simple; caudicles very short; pollinaria not hygroscopic following removal; and flowers protandrous by movement of the lip. Table 2 lists differences and similarities between Habenaria, Piperia, Coeloglossum, and Platanthera. Table 2. Differences and similarities of North American genera of the Habenaria complex. The generic treatment follows Luer (1975). Character Coeloglossum Habenaria Platanthera Piperia roots fusiform tuberoid usiform tuberoid anther cells diverging diverging diverging parallel (rarely parallel) anthero- slightly developed absent or absent phores developed developed viscidia protected by naked naked naked a membrane entire and stigma entire and bipartite and entire and 6 above spur lateral or above spur above spur orifice below spur orifice orifice orifice leaves cauline, cauline or cauline or basal, fugacious persistent basal, basal, persistent persistent distribution N. temperate, subtropical & N. temperate, N. temperate; arctic; E. & tropical; E. & arctic; E. & W. hemisphere W. hemispheres W. hemispheres W. hemispheres TAXONOMIC HISTORY OF PIPERIA The taxonomic history of Piperia, at both the generic and subgeneric levels, is complicated. The following is a chronological outline of nomenclatural changes. 1826: Sprengel briefly described the first Piperia as Spiranthes unalascensis Sprengl. based upon a collection from "Ins. Aleut.". 1828: Naming possibly the same collection as Sprengel, Chamisso described a short-spurred form as Habenaria schischmareffiana Cham. from "Unalasheae Aleutorum, ad radices montium passim". 1835: Lindley transferred H. schischmareffiana to Platanthera. He was aware of Spiranthes unalascensis but was not sure to what the name referred. In the same publication, Lindley was the first to describe a long-spurred member of the complex, Platanthera elegans Lindl. 1851: H. G. Reichenbach recognized Spiranthes unalascensis And H. schischmareffiana as the same but mistakenly placed the species in the spurless genus Herminium L. 1855: Hooker published Platanthera foetida Geyer but there was no description, only the name and references to the collection locality (plateaux of Spokan Mountains). 1855: Durand, apparently unaware of Lindley's Platanthera elegans, described a similar specimen and named it Gymnadenia longispica Durand. 8 1870: Bolander transferred Platanthera elegans to Habenaria. 1871: Sereno Watson provided a description of Platanthera foetida Geyer ex Hook., which is a short-spurred piperia, but he transferred the epithet to Habenaria. 1877: At this time Watson transferred Spiranthes unalas- censis to Habenaria and recognized H. foetida (Geyer ex Hook.) S. Wats. as a synonym of this new combina- tion. He wrongly referred Gymnadenia longispica to this species. Watson also, in the same publication, described a robust short-spurred form from the ... clay hills near San Diego, California" as Habenaria cooperi Wats. 1885: Greene described H. michaeli Greene, a long-spurred piperia from San Luis Obispo Co., California. This plant, according to Greene, differed from H. elegans by more