Pereskia (Cactaceae) LIBRARY. JAN 1 2 1987 BOTANICAL GARDEW BEAT ERNST LEUENBERGER Memoirs of the New York Botanical Garden Volume 41 Memoirs of The New York Botanical Garden ADVISORY BOARD PATRICIA K. HOLMGREN, Director JAMES L. LUTEYN, Curator of the Herbarium The New York Botanical Garden The New York Botanical Garden GHILLEAN T. PRANCE, Senior SCOTT A. MORI, Chairman, Vice-President for Science Publications Committee, The New York Botanical Garden and Curator The New York Botanical Garden EDITORIAL BOARD WILLIAM R. BUCK, Associate Editor The New York Botanical Garden Bronx, New York 10458 H. DAVID HAMMOND, Associate Editor The New York Botanical Garden Bronx, New York 10458 WALTER S. JUDD (1984-1989), Herbarium, Department of Botany, University of Florida, Gainesville, Florida 32611, U.S.A. AMY ROSSMAN (1984-1989), B011 A, Room 329, BARC-West, Beltsville, Mary­ land 20705, U.S.A. LESLIE R. LANDRUM (1985-1990), Herbarium, Department of Botany and Mi­ crobiology, University of Arizona, Tempe, Arizona 85281 U.S.A. MELINDA DENTON (1986-1991), Herbarium, Department of Botany, University of Washington, Seattle, Washington 98195 U.S.A. The MEMOIRS are published at irregular intervals in issues and volumes of various sizes and are designed to include results of original botanical research by members of the Garden's staff, or by botanists who have collaborated in one or more of the Garden's research programs. Ordinarily only manuscripts of fifty or more typwritten pages will be considered for publication. Manuscripts should be submitted to the Editor. For further information re­ garding editorial policy and instructions for the preparation of manuscripts, ad­ dress the Editor. Orders for past and forthcoming issues and volumes should be placed with: Scientific Publications Department The New York Botanical Garden Bronx, New York 10458 USA PERESKIA (CACTACEAE) Beat Ernst Leuenberger MEMOIRS of THE NEW YORK BOTANICAL GARDEN Volume 41 The New York Botanical Garden Bronx, New York 10458 ISSUED 4 DECEMBER 1986 Copyright © 1986 The New York Botanical Garden Published by The New York Botanical Garden Bronx, New York 10458 International Standard Serial Number 0071-5794 Library of Congress Cataloging in Publication Data Leuenberger, Beat Ernst, 1946- Pereskia (Cactaceae) (Memoirs of the New York Botanical Garden; v. 41) Bibliography: p. 129. Includes indexes. 1. Pereskia—Classification. 2. Pereskia—American - Classification. 3. Botany—America—Classification. I. Title. II. Series. QK1.N525 vol. 41 581 s 86-28483 [QK495.C11] [583'.47] ISBN 0-89327-307-4 Copyright © 1986 The New York Botanical Garden International Standard Book Number 0-89327-307-4 DECEMBER 1986 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 41: 1-141 Pereskia (Cactaceae) Beat Ernst Leuenberger1 Contents Summary 2 Introduction 3 Taxonomic History 4 Morphology 5 Habit 5 Roots 8 Development of the Stem and Its Appendages 11 Areoles 13 Leaves 15 Spines 15 Inflorescence 16 Development of Rower and Fruit 17 Receptacle, Receptacular Bracts, and Areoles 21 Sepaloid and Petaloid Perianth Segments 21 Androecium 23 Development 23 Stamens 23 Staminodes 24 Nectaries 24 Gynoecium 24 Ovules 25 Infructescence and Fruit 26 Seeds 29 Embryo 29 Cotyledons 31 Perisperm 31 Seedlings 31 Anatomy 34 Root Succulence 34 Epidermis : 34 Stomata 35 Lenticels 35 Periderm 35 Cortex 38 Sclereids 38 Crystals and Druses 39 Mucilage Cells and Cavities 39 Wood and Pith 40 Pollen Morphology 40 Phytochemistry 42 Chromosome Numbers 42 Evolution 42 Distribution 45 Ecology 45 Habitat and Climate 45 Phenology 46 1 Botanischer Garten und Botanisches Museum, Konigin-Luise-Strasse 6-8, D-1000 Berlin 33, Federal Republic of Germany. 2 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 41 Pollination 46 Dispersal 4' Conservation 4° Uses 48 Hybridization 50 Infrageneric Relationship 5 * Intergeneric Relationship 53 Systematic Treatment 53 Generic Description 53 Notes on Keys, Terms, and Abbreviations 55 Keys to Species of Pereskia 55 Key A for Flowering Specimens 55 Key B for Fruiting Specimens 57 Key C for Sterile Specimens 57 1. Pereskia aculeata Miller 58 2. P. humboldtii Britton & Rose 66 a. var. humboldtii 67 b. var. rauhii (Backeberg) Leuenberger 69 3. P. diaz-romeroana Cardenas 71 4. P. weberiana K. Schumann 73 5. P. lychnidiflora De Candolle 76 6. P. aureiflora Ritter 83 7. P. guamacho F. A. C. Weber 85 8. P. zinniiflora De Candolle 89 9. P. portulacifolia (Linnaeus) De Candolle 93 10. P. quisqueyana Liogier 97 11. P. bleo (Kunth) De Candolle 99 12. P. nemorosa Rojas Acosta 103 13. P. sacharosa Grisebach 107 14. P. grandifolia Haworth Ill a. var. grandifolia 113 b. var. violacea Leuenberger 116 15. P. bahiensis Gurke 119 16. P. stenantha Ritter 122 Insufficiently Known Taxa 126 Doubtful Names and Excluded Taxa 127 Acknowledgments 129 Literature Cited 129 Numerical List of Taxa 134 List of Exsiccata 134 Index of Local Names 138 Index of Scientific Names 139 Summary Leuenberger, B. E. (Botanischer Garten u. Botanisches Museum, D-1000 Berlin 33, Federal Republic of Germany). Pereskia (Cactaceae). Mem. New York Bot. Gard. 41: 1-141. 1986.—This monograph of Pereskia, neotropical genus of Cac­ taceae with 16 species, which range from southern Mexico and the Caribbean to northern Argentina and Uruguay, is based on the study of herbarium and liquid- preserved material as well as on the observation of seven species in the field and of all except one species in cultivation. The taxonomic history, morphology, anatomy, pollen morphology, phytochemistry, chromosome numbers, evolution, distribution, ecology, conservation, uses, hybridization, and infrageneric and in­ tergeneric relationships are discussed. Pereskia is a genus of deciduous trees, shrubs, and scramblers characterized by the presence of regular, slightly succulent leaves, bearing in their axils typically cactaceous areoles, i.e., brachyblast shoots 1986] PERESKIA (CACTACEAE) which produce spines and, in about half of the species of the genus, periodically also brachyblast leaves. Several species have tuberous roots. The predominantly receptacular nature of the flowers and fruits and the transition from superior to inferior gynoecia are described and illustrated. Besides paniculate and racemose inflorescences or single terminal or axillary flowers, proliferation from the recep­ tacles resulting in chain-like clusters of fruits is observed within the genus. Chro­ mosome numbers of In = 22 were found in the 13 species successfully investigated. The evolutionary origin of the genus and family may be sought in northwestern South America, as suggested by character correlations and distribution. Local uses of several species are known; the planting of living fences and hedges being the most widespread. Separate keys for flowering, fruiting, and sterile specimens are provided in the systematic treatment. All 16 species are illustrated by line drawings of relevant parts. The generic concept follows that of previous monographers (Britton & Rose, 1919; Vaupel, 1926) and includes Rhodocactus (Berger) F. Knuth in the synonymy of Pereskia. No formal infrageneric classification is upheld. Sixteen of the previously described 59 species are recognized; 26 names are placed in synonymy and 17 are doubtful or excluded from the genus. The list of correct names as accepted here includes: Pereskia aculeata Miller, widespread with dis­ junct distribution, recurved geminate spines, and fragrant flowers; P. humboldtii Britton & Rose, P. diaz-romeroana Cardenas, and P. weberiana K. Schumann, tuberous-rooted Andean species with small leaves, flowers, and fruits; P. lychni­ diflora De Candolle, an orange-flowered tree with primitive floral characters; P. aureiflora Ritter, only recently described; P. guamacho F. A. C. Weber, a tree with small yellow flowers appearing during the leafless stage; P. zinniiflora De Candolle, P. portulacifolia (L.) De Candolle, and P. quisqueyana Liogier, endemics from the Greater Antilles and distinctive for their dioecious flowers; P. bleo (Kunth) De Candolle, a shrub with petiolate leaves and bright red flowers from mesic forest habitats in Panama and Colombia; P. nemorosa Rojas Acosta, P. sacharosa Gri­ sebach, P. grandifolia Haworth, and P. bahiensis Giirke, pink-flowered species with medium to large leaves, all of South American origin; P. stenantha Ritter, closely related to the former but distinctive for its urceolate-campanulate flowers. One new combination, P. humboldtii var. rauhii (Backeberg) Leuenberger, is nec­ essary, and one new variety, P. grandifolia var. violacea Leuenberger, is described in this paper. Introduction Pereskia is a genus of 16 species of neotropical trees and shrubs. It differs from typical succulent Cactaceae in its woody habit and the presence of normal leaves and is therefore not always easily recognized as a member of the family at first sight. However, it exhibits the basic characters of the family, namely the spine- bearing areoles and the peculiar nature of the floral cup which incorporates few to many leaf-bearing nodes. Other floral characters distinctive of the genus and the family include: numerous perianth segments, spirally arranged centrifugal stamens, and a gynoecium of few to many connate carpels, adnate to the recep­ tacular cup. The superior to inferior ovary is more diverse in Pereskia than in other genera of the family, where it is always distinctly inferior. By reason of its general habit and the morphological and anatomical features of its stem, leaf, and flower, Pereskia is generally considered to be the most