Image 2 © 2014 . All rights reserved.


I grew up on a farm in deepest rural (almost feudal) England. I went to London University and then to America to do a Ph.D. at City University of New York and the New York Botanical Garden. I started work at the Garden in 1987 and since then have been doing research on the systematics and ecology of the palm family.

Arecaceae; Asterogyne martiana

Asterogyne martiana, a fly pollinated palm, growing in Costa Rica

 How did you become interested in palms?  I first became interested in palms almost by accident. Just before I came to America, I was sitting outside a pub on Kew Green, watching a game of cricket. A botanist from Kew Gardens, whom I knew quite well, stopped by. I said “Ray, I am going to do a Ph.D. in New York. What is a good group to study?” He said “Oh, you should study palms because the big expert in the States has just died and no one is working on them”. I became interested in pollination after doing a short study on the pollination of a palm in Costa Rica. I was just fascinated by the intricate interaction between the palms and the insects – all taking place deep in the forest at night. No one knew about it.

How has the study of palm pollination evolved from when you began? When I first became interested in palm pollination, in the early 1980s, there was a widespread belief that palms were mostly pollinated by wind. This was a ‘Eurocentric’ view, based on European botanists’ belief that palm inflorescences were similar to wind-pollinated plants from the northern temperate zone. How wrong this turned out to be! In the past 30 years we have seen ever more amazing instances of palm pollination, with different species being pollinated by bees, beetles, flies, bats, birds, and mammals. Often there are intricate and complicated interactions between the palms and the pollinators.

Image 7This palm is related to Phytelephas, with very unusual inflorescences (male one illustrated here). This picture was taken in Ecuador, with my friend Henrik Balslev.

Tell me about some of the first discoveries of palm pollination. In 1970 a researcher in Costa Rica carried out one of the first modern pollination studies. He showed a complicated pollination system involving the palm Asterogyne martiana and syrphid flies. Myself and colleagues also worked in Costa Rica and studied pollination of a palm named Cryosophila. The inflorescences were tightly enclosed by bracts. Early in the morning, around 4 am, the whole inflorescence heated up, gave off a strong, musty scent, the bracts opened at the tip of the inflorescence, and many small nitidulid beetles and weevils arrived. At this time the pistillate flowers were receptive. Later, the stamens opened, covering the beetles with pollen, and the following night they would leave, looking for another opening inflorescence.


                                       Courtesy of the US Forest Service

What other palms are pollinated by beetles?  The ivory nut palms, Phytelephas species, have very unusual inflorescences, with the male ones elongate with thousands of small flowers, some with up to 1200 stamens per flower. The pistillate inflorescences are quite different, with few, large flowers borne in a tight cluster. They are pollinated by rove beetles, staphylinids, and up to 20,000 beetles were counted from a single inflorescence. Inflorescences of both staminate and pistillate plants heat up as the flowers open, reaching up to 19˚C above ambient temperature. Female beetles constructed egg chambers in the staminate inflorescences, oviposited, and then sealed the chamber with pollen. The larvae hatched very quickly and immediately began to eat the pollen. Like other beetle pollinated palms, all this activity took place at night. The authors of this study pointed out that the pollinating rove beetles were closely related to another group of staphylinids that reproduced in fleshy mushrooms.

Tell me about bats pollinating palms.  Again in Costa Rica, where a lot of ecological research has been carried out, a group of understory palms in the genus Calyptrogyne have unusual, unisexual flowers but both staminate and pistillate are borne on the same, long, thin inflorescence. The top of part of the flowers can be removed from the rest of the flower, like a cap. This fleshy, sweet tasting cap is eaten by nectar-eating bats (Phyllostomidae: Glossophaginae). They swoop down on the inflorescences at night, and eat the cap from flowers. When they eat the cap from the staminate flowers they become dusted in pollen, and in eating the cap from a pistillate flower they deposit pollen on stigmas. Another interesting aspect of the interaction is that small mites, living on the inflorescences, are transported from palm to palm by the bats.


Image 3

Calyptrogyne in Costa Rica. This is a bat pollinated palm with long inflorescences sticking up above the leaves.

And mammals pollinating palms?  Most recently, and most remarkably, researchers in Malaysia have discovered that a palm, Eugeissona, is pollinated by small mammals. The inflorescence is a huge affair, sticking up above the leaves of the palm. Flowers give off copious amounts of nectar, and this nectar has the highest alcohol concentration of any natural food. This is achieved by specialized flower buds that have fermenting yeast present. During the night, numerous small mammals, especially pen tailed treeshrews (Ptilocercus lowii) visit the inflorescence and pollinate the flowers. They also drink the alcoholic nectar. Equivalent amounts of alcohol would intoxicate humans, but the tree shrews don’t get drunk!



 What is the best part about the work you do?  The excitement of discovering things that were not known before. Even now I still feel this. I am now carrying out a revision of a large genus of palms, Calamus, the rattan genus. Much of the work is routine, laborious, but occasionally there are moments of understanding.

What is the worst ?  Things that distract me from working.

Can you talk a bit about balancing your work and family?  I am lucky to have a forbearing wife who puts up with my absences.

What are your vices?  None. I gave them all up years ago.

What kind of pets do you have?  We have a dog, a Westie, called Lucy.

What is the last wild animal you saw? Squirrel. This morning, walking the dog. I thought, boy, it must be cold for that poor squirrel today (3°F this morning in New York!).

(Photo at the top of this post: collecting palms on the Ledo road, in northern Myanmar)

For more information about Andrew :

On February 11, 2014 The World Wildlife Fund and The New York Botanical Garden released a new book by Dr. Andrew Henderson and Dr. Charles M. Peters: Systemics, Ecology and Management of Rattans in Cambodia, Laos and Vietnamon-The Biological Bases of Sustainable

A selection of other books by Andrew:




Note from Irene: One of my favorite jobs when I lived in New York was working for Andrew at the New York Botanical Garden. I have very fond memories of going through the herbarium which holds a collection of more than seven million preserved specimens featuring all plant groups: flowering plants, ferns, conifers, mosses, liverworts, algae, fungi and lichens.  I loved opening the fragrant folios of dried palm leaves, inflouresence, fruit and trying to capture them on paper.  Seventy of my palm drawings are included in Flora of the Venezuelan Guayana.


Palm 40



 This post was originally posted March 4 2014

If you would like to subscribe to Light Seeking Eyes, type your email address in the subscribe box at the bottom of this page. You will receive a new post once or twice a month.






  1. That warm-blooded creatures are pollinators is still a revelation to many and who’d have thought that a shrew can drink you under the table! Thanks for this wonderful interview and letting us see these exquisite early-Olivieri botanical line drawings!!

  2. It’s always fun to get a look at someone else’s passion and this was fascinating. Especially love that a random encounter with a colleague led to Dr. Henderson’s life’s work. Thanks for this interesting peek behind the scenes.
    (Personally, I thought that treeshrew looked like it had a little buzz on.)

  3. ellen

    Seriously Fascinating!!!!
    Thank you Andrew and Irene!
    Wonderful photos and drawings ! Nature at her most secretive and extravagant .

Leave a Reply

Your email address will not be published.
Required fields are marked:*