Vol. 11, No. 3~i SEPTEMBER 1988 I.A.S. Board of Directors AROIDEANA is an illustrated quarterly devoted to information about Moids and published by the International Aroid Society, Inc. All materials may 1986-1988 be reprinted or quoted with customary acknowl­ edgment to the author and Aroideana. Manu­ Eugene Fike, Dr. James McArthur, scripts, corrected proofii and all editorial corre­ Bob See, Maree Winter spondence should be sent to: Craig Morell, clo lAS, PO. Box 43-1853, Miami, FL 33143. 1987-1989 Scientific Manuscripts Papers must be typed on standard letter-size paper, John Banta, David Burnett, Dewey Fisk, double spaced throughout, on consecutively num­ Patricia Frank, David Leicht, bered pages, with 2.5 cm (1") margins on all sides. Susan Staiger Papers may be submitted on 51/4 inch floppy disk using Microsoft Wordstar: Version 4 on mM or MS.DOS 3.0 or less, accompanied by a printout 1988-1990 with right margins unjustified. Authors should Chuck Hubbuch, Jim Black, follow recommendations of the Council olBiolog· ical Editors Style Manual. Measurements are to be Denis Rotolante, Joan Hackler, in metric units. Doris Ross, Luis Bueno Sequence 01 Sections Follow this order: title, author name and address, Honorary Board ofDirectors abstract, introduction, materials and methods, Dr. Michael Madison: California results, discussion, acknowledgments, literature cited. Captions must accompany all tables and Roberto Bude-Marx: Brazil figures. Abstracts should summarize the character Sue Thompson: Pennsylvania and scope of the paper in 250 words or less, Bette Waterbury: President Emeritus, followed by no more than 8 key words. Literature Florida cited must be referenced in the text and listed alphabetically by author, with journal titles spelled out. Officers Illustrations President: Dewey Fisk Line drawings and tables must be in black, Vice-President: Chuck Hubbuch high-resolution ink, clearly labeled and consecu­ tively numbered. Photos must be completely Treasurer: Patricia Frank labeled and show desired cropping. Figures will be Recording Secretary: Maree Winter published either (one-column) 6 cm or (two­ Corresponding Secretary: Donna Rich columns) 12.6 cm wide. Full page illustrations will Membership Secretary: Bruce McManus be no more than 12.6 X 20 cm. Original art will be returned on request. Figures will be published in black and white, unless special arrangements Newsletter have been made with the editor for reproduction Editor: David Leedy in color. Processing Manuscripts Upon receipt, manuscripts are acknowledged and Aroideana sent for critical review. Accepted manuscripts are Editor: Craig Morell sent to authors for revision in consideration of Co-Editors: Dr. Thomas B. Croat reviewers' comments, and returned to the editor for typesetting. Page proofii are sent to the author Amy Donovan for proofreading, with any changes other than Production Manager: Dr. Glenn A. Long tyjJQgraphical errors being charged to the author at cost Authors with research support will be billed for page charges at the rate of $30.00 per Consulting Editors printed page at the editor's discretion. Dr. Monroe Birdsey, David Burnett, Voucher Materials Dr. Thomas B. Croat, Dr. Simon Mayo, Descriptions of new species require deposit of Dr. Dan H. Nicolson, Dr. Derek Burch type materials in a recognized public museum. CONTENTS Thomas B. Croat Ecology and Life Forms of Araceae. 4 Appendix I ............ 21 Appendix II . 23 Appendix III . 40 Literature Cited . 49 Index ..... 53 Published: September, 1990. This issue completes Volume 11 ofAroideana. Although published as Vol. II, No.3, the contents herein represent a double issue, Vol. II, Nos. 3 and 4. Photos: All photos accompanying this issue of Aroideana are by the author, unless otherwise designated. Front Cover: Monstera dilacerata (K Koch & Sellow) K. Koch; typical juvenile leaf form. Back Cover: Monstera dilacerata (K Koch & Sellow) K Koch; hemiepipytic vine. 4 AROIDEANA, Vol. 11, No.3 Ecology and Life Forms of Araceae Thomas B. Croat Missouri Botanical Garden RO.Box299 st. Louis, Missouri 63166-0299 INTRODUCTION casts a darker shadow) where a physio­ Araceae, a family of herbaceous mono­ logical change takes place allowing them cotyledons with 106 genera, is a com­ to grow toward light (Strong & Ray, plex group in terms of life form and 1975). They grow as appressed epi­ ecology. The family is widespread, with phytes on trees or as vines in the canopy. almost an equal number of genera in Others begin their lives as true epi­ both the Old and New Worlds, but with phytes, some reconverting to hemiepi­ the majority of species occurring in the phytes by producing long, dangling roots New World tropics. A few genera range contacting the forest floor below. into north temperate regions with one species ranging to at least 63 degrees Some species, especially members of north latitude. Few aroids range into subfamily Monsteroideae, have heterob­ temperate regions of the southern hemi­ lastic development with leaf and stem sphere; the most southernly being Pistia morphology reflecting the differences in stratiotes L., which can be found through their growth phases. Juvenile plants may 36 degrees south latitude in Argentina. produce a small terrestrial rosette of The family occupies a wide variety of life leaves, then grow rapidly, producing a zones and habitats throughout its range, few small leaves on long internodes. The extending from tropical dry to pluvial preadult leaves of the first hemiepiphytic rainforest, but also ranges into subarctic phase of such plants are often very marshes, tropical swamps, cloud forests, distinct from the adult leaves. Many such cold windswept montane plains and species are able to convert again and semi-arid to arid coastal plains. The again from adult growth (consisting of family has many species which will not short, thick internodes) back to juvenile tolerate any degree of frost or cold such growth (with elongate internodes bear­ as Anthurium brownei Masters, as well ing smaller leaves), either to establish as some, like Symplocarpus foetidus (L.) more adult plants with a rosette of leaves Nutt., which actually emerge from snow­ or to survive the dynamics of an ever­ covered ground. changing forest, complete with treefalls The most interesting aspect of the and falling branches (Ray, 1987). Other family's ecology is the diversity of adap­ hemiepiphytic species are vines which tive life forms. These range from sub­ branch and produce growth throughout merged to free-floating, and emergent the lower and middle levels of the aquatics to terrestrial plants and to canopy. These species (e.g., Philoden­ epilithic or epiphytic forms which may dron scandens K Koch & Sellow) ac­ be true epiphytes or hemiepiphytic complish long-term survival by having a (growing on trees but rooted in soil). portion of their biomass in a part of the Hemiepiphytism is diverse itself, with canopy which survives any particular some species beginning their lives as treefall (Pefialosa, 1975). Even true epi­ terrestrial seedlings, then growing phytes rarely succumb promptly to a fall skototropically (toward darkness) until from their host tree, but instead con­ they arrive at the nearest suitable tree tinue to flower and fruit on the ground ( usually a relatively large one which for a limited time. T. Croat, 1988 5 DISCUSSION by only one genus, with one pantropic The following is an outline and discus­ and variable species. Pistia stratiotes L. sion of life form diversity in the Araceae has a short stem and a rosette of (see Appendix III for a glossary of aerenchymatous, buoyant leaves, with a terms): cluster of fine, hair-like roots below. It 1. Aquatic plants occurs mainly at lower elevations and 1.1 Submerged aquatics inhabits mostly open, fresh waters at the 1.2 Free-floating aquatics edges of slow-moving streams, lakes and 1.3 Emergent aquatics ponds. This species is remarkably suc­ 2. Terrestrial plants cessful in using mostly vegetative repro­ 3. Epilithic plants duction, often totally clogging small to 4. Epiphytic plants large waterways in a short period of 4.1 Hemiepiphytes time. Vines Appressed climbers 1.3 Emergent Aquatics 4.2 Epiphytes Emergent aquatiCS make up a very large group within Araceae. Many genera 1.1 Submerged Aquatics have at least some species which spend Jasarum steyermarkii Bunting has per­ all or part of their lives rooted in manently submerged leaves and is the standing or moving water. Temperate only true example of this life form North America is particularly rich in among neotropical Araceae. It grows aquatiC or semiaquatic genera. Most, rooted in moving streams on the escarp­ including Acorus, Calla, Lysichiton, ment of the Guayana Highland where it Orontium, Peltandra and Symplocar­ is endemic (Bogner, 1985). When it pus, grow in swampy or marshy areas, flowers, the scape is protruded above lakes, ponds, or along the edges of the level of the water. Many rheophytes, creeks. Arisaema triphyllum (L.) Torr. however, may spend a portion of their is also reported as sometimes occurring lives underwater with no apparent harm, in swampy areas (Small, 1933; Correll & but flowering occurs when the plants are Correll, 1972). mostly emerged and have only their Some emergent aquatics, e.g., Mon­ short stems below water. Species of trichardia arborescens (L.) Schott, Pel­ Acorus, Anubias, Lagenandra, Spa­ tandra virginica (L.) Kunth, Cryptoco­ thiphyllum and especially Cryptocoryne ryne ciliata (Roxb.) Fischer ex. Schott are used as aquarium plants and may be (D. Nicolson, pers. comm.) and Typhon­ submerged completely for indefinite pe­ odorum lindleyanum Schott O. Bogner, riods of time without apparent injury. pers. comm.), occur in tidal zones. Even Dieffenbachia has been used in While most emergent aquatiC genera aquaria (D. Nicolson, pers. comm.) in the neotropics are well-rooted, terres­ The Asian tropics, in contrast to the trial plants, some are epilithic, such as a American tropics, have large numbers of rheophytic group of Anthurium (A.