Detailed Description of the course

(Please, Click here for more information about dates and costs of the course)


Field practices and special skills gathered by students
The Hosting Institution TSC
Field Trips , Clothing
A new way to determine plants
Content of the course
The Tropical Dendrology course offered in Costa Rica
Costs and Financing
To whom is the course addressed



Field plant identification is a challenge faced every day in the tropics. Many professionals involved in biology studies would like to master an easy method to know, in the field, the scientific names of the plants they are dealing with. Some times people would be very pleased even just by knowing the genus or the family, or just the order of the plants. A method solving these types of problems is offered every year by the Tropical Science Center, in Costa Rica, offering a two-week course of Tropical Dendrology, which is offered one time in English (June-July) and one time in Spanish (March or April).





The Tropical Science Center (TSC) was founded in 1962, by Dr. Leslie R. Holdridge an other scientiests, as a private Costarrican non profit association. Its objectives are to conduct and support scientific research and education, and to encourage the acquisition and application of knowledge concerning Man's enduring relationships with the resources - biological and physical - of tropical environments. The Center established its Continuing Education Program in 1992. The Center also offers private consultancy in these and other subjects. There is a link at the bottom to a webpage on the Tropical Science Center.



The Center was currently receiving support in the past to partially finance these courses from the World Wildlife Fund (WWF) - Central American office, headquartered in Turrialba, Costa Rica. Also students hve found support from several institutions that assign them fellowships, namely the International Tropical Timber Organization (ITTO) -  headquartered in Tokio, Japan.





Dr. Leslie Holdridge developed a procedure to know the tropical plants in the field, by means of simple, fresh characteristics of non reproductive organs (leaves, twigs, bark, odors, tastes, exudations, buttresses, etc). Later on, we add new learning techniques.

This way, it is possible to teach how to identify plants down to family level or down to genera level (and, in some cases, down to species level) during the traditional university quarterly courses, or in a short two-week course, as explained below.

This methodology has been used by some professors in Forestry Schools in Latin America. Such a methodology has been adapted by Dr. Humberto Jiménez Saa, Course Manager, to successfully teach our two-week Tropical Dendrology course we have been offering in Costa Rica.

After you finish reading this page, you are invited to visit our page "Articles about our duties" and find Article 1: "A new efficient methodology to teach plant determination in the tropics" there you will read about pedagogical basis of the course.



The course is offered every year in Spanish (March or April) and in English (June-July) and is given in four different enviroments (Life Zones). Dates of next courses are given in the correspondent page (Course on Tropical Dendrology)

The Tropical Dendrology course is devoted mainly to teach predetermination techniques as stated in our article " "A new efficient methodology to teach plant determination in the tropics"", found in the "Articles about our duties" page of this Website.

The course sequence followed to teach the various subjects is very important. For example: at the beginning of the course, students learn those groups which are very easily recognizable and common in the surroundings. When the course advances, instructors show those groups of plants which are increasingly "difficult to be recognized" and rare or less common in the surroundings. At the end of the course they teach those species which do not fit with the normal characteristics of its group (the exceptions).

Students are urged to examine three characteristics to typify genera and families, namely: leaf class (simple, different compound types), leaf arrangement (opposite, alternate, etc), and the presence and types of stipules. Combining these three characteristics with others such as type and color of exudates, pellucide-punctate structures, leaf blade consistence, nectaries, odors, etc, there appear short descriptions which are very easy to be memorized, and which enable students to predetermine most of the plants.





The course is addressed to professionals and lay persons in biology, forestry, biodiversity, birding and ornithology, ecology, agroforestry, ethnobotany, field guiding, and other areas in the natural resource field. Also professional taxonomists, working both at the herbarium or in the countryside, have attended the course.

They found themselves well prepared to identify plants in the herbaria, but they usually failed when they tried with fresh samples in the field. For instance, we want to mention that in one group there were four students with Ph.D. degrees attended the Dendrology course in English: Dr. Ed Jensen, Professor of Dendrology at Oregon State University; Dr. Dwight Smith, Professor at West Indies University in Jamaica; Dr. Keith Shawe, plant taxonomist working for The Natural Resources Institute in Kent, England and starting a field work in Belize; and Dr. Marco Gutiérrez, Professor at Universidad de Costa Rica in San José.

It was another group when Dr. Silviano Camberos Sánchez, and Dr. Mark Plotkin, author of the bestseller
"Tales of a Shaman's apprentice; an ethnobotanist searches for new medicines in the Amazon rain forest", also attended the course as students.

We want to stress the point that, although the course has proven to be of great help to people with experience in dendrology, it is not necessary to have that experience to take advantage of our course. For instance, the mentionned group with four students with Ph. D degree, was also attended by a tourist guide, a student of Biology, and a specialist in computer science whose hobby is botany. Other students were teachers of Biology at high school level in Colombia and in France, and others were curators of Herbaria in Ghana (Africa), and field foresters in Costa Rica.

All people mentioned in last three paragraphs gave excellent references about the course (both academic level and organization).
Some of them found the event as being both an excellent course and also an exciting travel through Costa Rica. The reason for this appreciation is because we visited four different habitats: the Central Valley (Premontane Moist Forests) the Monteverde Cloud Forest Preserve, the Guanacaste region (Dry Forest), and the Atlantic region (Moist and Wet Forests).
Additional comments, as well as TESTIMONIES BY FORMER PARTICIPANTS, can be read at the "Testimonies" page for this Website.



The course lasts two weeks and stresses on field practices. Some theoretical aspects are covered, such as reviewing basic terminology necessary to describe trees and shrubs; efforts are made to teach those characteristics used both in dendrological literature and in species identification. Information on major uses of species found in the field are also given.

During the course we teach the basis for tree and shrub identification in the American tropics, by means of non reproductive characteristics which can be recognized and described in the field, by using a field botany lens. Students are trained to identify a high proportion of Neo-tropical species down to family or genera levels; and they are also able to identify down to species level some important trees and shrubs found in Costa Rica. (See also the paper "A new efficient methodology to teach dendrology in the Tropics" in the page "Articles about our duties" o this Website).

Students normally gain special skills enabling them to continue making progress in species identification on their own after working in their countries. For instance: students draw plant samples, and prepare a personal matrix in which he / she arranges most of the taxa (families and genera) according to their outstanding characteristics. Having these skills they may use Internet (for instance the "image" device in Google) to obtain valuable information. This devices allow the student to quickly define a few taxa that finally lead him/her to identify the samples he / she is working with during the course practices. Such devices are also the basis for the student to prepare a personal matrix specially designed for the site where he /she will work in the future.

Our experience says that when people go on the normal way of learning species by species, they will take several years to learn the plants of, say, the Monteverde region. But when people go to the groups of plants (i.e. families or group of families) they make progresses very very fast when they want to identify the plants of a region. And they go even faster when they move to another region and start learning a new group of plants. On the contrary, when they have learned -for instance- the plants of Monteverde going species by species and, after that, they move, say, to the Atlantic Region, they have to start since the begining and will pass several years until they master the new group of plants of that region.



Four regions will be visited, as follows:

Week one  At the beginning we will spend some days in the Central Valley, around San José. Places to visit range from 600 to 2,300 meters above sea level; average temperatures go from 22 to 11 degrees Celsius; annual average rainfall goes from 1,200 to 2,500 mm.

Then we go to the Guanacaste province. Places to visit range from sea level to 300 meters above sea level; average temperatures go from 28 to 24 degrees Celsius; annual average rainfall goes from 1,600 to 2,500 mm.

Week two.   We also visit the Monteverde Cloud Forest Biological Reserve, owned by the Tropical Science Center. Finally we spent the last days in the Atlantic region. Places to visit range from sea level to 300 meters above sea level; average temperatures go from 28 to 24 degrees Celsius; annual average rainfall goes from 4,000 to 6,500 mm.

Local trip schedules could be modified by group leaders for the benefit of the group, as may be demanded by circumstances out of our control.

CLOTHING: Costa Rica is entirely located within the tropics. Thus, lowlands are hot the year around and high elevations are warm and a little bit cold, especially during the night. We visit Monteverde, where the annual mean temperature is 17 degrees Celsius and can get down to 12 degrees Celsius, especially during the night and early in the morning. Thus, bring a light-weight jacket. For field trips we suggest not wearing bermuda shorts but pants instead, even in the lowlands. As for footwear, we suggest waterproof hiking shoes; welingtons are not indispensable; but you may select what you consider more comfortable. A light rain coat with a hood is always welcome. A light hat or cap, and a small transparent plastic umbrella to protect notebooks and equipment while working in the field, are excellent ideas.



Dr. Humberto Jiménez-Saa (Tropical Science Center; dendrology consultant in Colombia, Surinam, Venezuela, Costa Rica)
Ms. Willow Zuchowski (Author of several books on costarrican plants)




1. Plant morphology.   Macroscopic characteristics of trees and shrubs, used in identification (trunk, roots, branches, leaves, flowers, fruits, exudations, odors, colors, etc)

2. Fundamentals of taxonomy and dendrology.   Classification, nomenclature, identification.  .

3. Identification of tree and shrub plants (family and genus levels).   Taxum description; predetermination and determination of species.   Current information on actual and potential uses of taxa found in the field.   This is the main part of the course.

4. The use of practical techniques to gather and present class information, such as plant drawings, plant descriptions, personal keys or matrixes. Preparation of simple dendrological keys, based on fresh plant material. Preparation of a personal matrix to "assemble" all dendrological information gathered during the course.      The use of dendrology literature.   Exercises using tropical dendrological literature such as field manuals, keys, dictionaries, checklists, and the like.   Procedures to verify accurate identity of species.



Total cost is US$ 1,600.00 or its equivalent in Costarrican colones, which covers:

Registration Fees
Class materials
Lodging and meals
Course-related local transportation
Farewell dinner
and Certificate
  Airfare is not included.



To apply, please fill out and submit the Registration Form. Candidates will be evaluated as their applications are received and will be notified as soon as possible of their acceptance.


Please click here to visit a webpage on the
Tropical Science Center

Dr. Humberto Jiménez-Saa Curriculum Vitae
Tropical Science Center
P.O.Box 8-3870-1000
San Jose, Costa Rica

Fax: (+506) 2253-4963
Phone (Ofice):(+506)2253-3267
Phones (Home): (+506) 2231-1236
(+506) 2291-0862




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