This listing is for just one genus: Dudleya. This document may be changed at any time in the future as new or better data becomes available. Suggestions and new data are always welcome.

Note: This list agrees with the data found in the Lexicon of 2003.

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This is just one part of my listing of all known species of family Crassulaceae found native to North, Central and South America.

Alphabetical listing of all known New World species in family Crassulaceae.

GENUS DUDLEYA

PREPARED BY JAMES E. LOW

Last updating: 7 Feb. 2008

INTRODUCTION

The Dudleyas constitute one genus within family Crassulaceae. This genus consists of a hundred or so species plus a few subspecies in three subgenera. All are native to the southwestern parts of North America on its coast, on its islands, the coastal mountains and deserts. Almost all of the species have succulent leaves arranged into rosettes. Because of these interesting rosettes some are quite attractive, some are useful as decorative plants for pot growing, or for garden use wherever climates are suitable. Many have leaves that are “glaucous”, (white coated), this feature adds to their beauty and interest.

These plants can be a fascinating group to collect and study as a hobby. Unfortunately, they have been largely neglected until now. Some are rare and difficult to obtain, either as seeds or as plants. This fact may attract the interest of the rare plant buffs. The literature is mostly sparse and often greatly out-to-date. Some work remains to be done by botanists in refining the classification, in preparing more useful texts, and in obtaining good identification photos, and drawings, and in making these widely available. To the scientist this group can be interesting in regards to its line of evolution. Facts regarding evolution are now becoming better understood as new techniques become available for use in this research.

For the beginner who wishes to learn about this plant group, here are some things they will need to know. First will be the need to gain a good concept of the entire Dudleya genus in all it’s of 3 subgenera. Next is to understand how it fits within family Crassulaceae. Later, for those advanced enough to have an interest in plant evolution come such questions as which ancestor species did this genus most probably evolve from, and how did all of them end up in their present day habitat locations. Botanists now believe their current habitat range may be located far from where it started in pre-historic times.

The beginner should try to actually see as many as possible of the species as the living plants. This is one of the best ways to become well acquainted with this charming group. If this is not possible for some species, it then becomes necessary to rely on good photos or drawings. Below I will list sources for some such pictures. One difficulty soon becomes evident. Good pictures of these plants are not easy to find. Perhaps this difficulty should be seen merely as a challenge for plant lovers who want to learn more.

How can actual plants of all species be obtained? This is now difficult to almost impossible for all the less common species. Suggestions will be offered below. Then: once you have the plants, how can they best be grown far from their native locations? In this introduction I can attempt to provide some answers. This will be followed by an alphabetical listing of all the known wild species, and most natural hybrids. For each species I will give some useful and interesting facts. Of course a short listing like this cannot provide all the desired facts, but this author hopes that it can serve as a good start. Wherever it is possible references to more complete texts will be made within these species listings.

THE SWISS GLOBETROTTERS

Photos of the more common species of Dudleya are easily available, but what about photos of the many lesser known, and rare species? Usually these are more difficult to locate, and some are almost impossible to find. I am happy to report that a man and wife team of photographers from Switzerland made a tour of all known Dudleya habitats around year 2000 to take photos, and to record habitat conditions for all species in genus Dudleya (and now they are doing the same for other genera in this family). They were quite successful, and they found almost every valid species, and got multiple photos of each taken as a “botanical series” for displaying all the important characteristics. All of these photos are high definition digital photos. I have access to them for viewing.

Note that they maintain a large Internet website in English and German for displaying the results of their continuing research. Their Dudleya photos number more than 2000 in their files, and they cannot place all of these on the website. For now they display on line only some of the best views of each species. This couple does their research for scientific purposes, and not for profit. They now live in Central Mexico in semi-retirement, and they continue their touring of all sites in North, Central and South America searching out every species in family Crassulaceae, plus some other plant groups (no cacti). These people are Martin Kristen and Julia Etter. They call themselves the “Swiss Globetrotters”. They want botanists of the world to know that they will make the results of work available to scientists for scientific purposes, if they receive a formal request for it.

Anyone can view their website for free. It is at <http://www.globetrotters.ch> and it emanates from Switzerland. It is divided into several parts, and any new viewer is best advised to get acquainted with all of these website sections first, and especially interesting may be the many travel logs. Then viewers should go to the section called “Crassulaceae” for viewing all American species within this family. The layout is done in a way best for scientific purposes. Each species can be accessed by easy standard search methods. All species in all genera are named; photos appear with these website names only after the habitat has been visited by them (thus many listed species are now without). They normally display up to 6 views per species, and each can be enlarged from thumbnails, but cannot be printed out without their knowledge and permission. These people can be accessed personally at < Cette adresse email est protégée contre les robots des spammeurs, vous devez activer Javascript pour la voir. > (if they are not away on one of their tours, normally of several weeks each: and these are to continue into the future for quite some time). Some of their fine photos are presented in several well known journals on cactus and succulent plants from time to time.

Since they do all the work of maintaining their website, adding new photos is often delayed when they are away for prolonged periods. They may at some time decide to publish their own books on plants, and on their travels, but this will not be until after they retire from active searches sometime in future years. They like to have contact with botanists of all countries where possible.

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MY LISTS GO ON LINE!

In late 2007 I became acquainted with Margrit Bischofberger of near Zurich, Switzerland as a result of on-line discussions with Ray Stephenson of the Sedum Society in England, and with my long time friend Helmut Regnat of near Munich, Germany. Margrit had been told about my lists of American native Crassulaceae, and so she asked to see them. She is leader of a group starting a new website about the Crassulaceae. She liked my lists well enough to discuss them with Jean-Michel Moullec of the Roscoff Exotic Garden in western France. He has long had a large website about Cacti and succulent plants. Margrit and Jean-Michel requested that they be permitted to use my lists for the new Crassulaceae website, and I agreed. Soon the first of my lists was on line with one great new advantage. I had never been able to add pictures of the plants. Mr. Moullec had many excellent photos that could be added with each of my species listings and he did that beautifully.

Photos for some species were not available, so we asked Helmut Regnat if we could use his many fine photos, and he agreed! Helmut and I have long worked together on our plant records. Later I told Guillermo Pino of Lima, Peru about the project. He has been doing excellent research on the Crassulaceae and other families of plants native to Peru, and he had plenty of photos of these. He also agreed to supply his photos, and in time we should be seeing good photos of these plants that had never before been seen in photos. Maybe we can also get photos from other people as this project continues. Maybe in time we can have photos for every species! It now appears that this new website will be a very useful resource to all people of the world interested in these plants. This is more like what I always wanted in order to realize the potential of the Internet for this purpose. We hope it continues to grow, and that more and more people offer photos and data, plus constructive suggestions. Right from the start it has been a truly international project.

My lists were started many years ago, and were mainly for personal use, and for the use of friends. I’m no professional at this, so I must work to update and improve my lists before they go on line, no doubt with some errors remaining, and much poor wording. As I write it is February of 2008, and I am age 85, and working from my home near Sacramento in northern California, USA. I hope I can still continue to maintain my lists for some years; but after I am gone, I hope that there will be someone able and willing to continue what I started. Lists are never fixed: new species and changes must be added from time to time, and this task will never end. Someone has to keep up with these things and make needed changes as soon as practical in order to keep the lists always current and dependable. This kind of work is not done for pay, so volunteers are needed. I decided to add this paragraph in order to answer unspoken questions in the mind of users of these lists. Can you also help us in this non-profit effort? (contact Margrit) Many users will appreciate it.