Far from being a dead art form, botanical prints and original watercolours are very much alive. There is a thriving Botanical Art School in Melbourne (see My Collection) and some of the artists involved are selling their work for considerable amounts. It's easy to see why when you study the detail from Jenny Phillips's Rococo Tulip.

Although this is primarily intended as scientific illustration, it has the emotional power of contemporary fine art. There are many who would prefer to hang this on their wall than a Brett Whiteley print.

The older work fetches the highest amounts at auction but original contemporary work is also sought after. Jenny Phillips is regarded as Australia's leading contemporary botanical artist but she says there are at least 20 exceptional artists worth collecting, including Fiona McKinnon, Stephanie Goss, Bev Allen and Susanna Blaxill.

Time will tell whether any modern work reaches the heights of original watercolours by Pierre J. Redoute. Born in 1759, Redoute is considered one of the grand masters of botanical art. His lesser originals can still be bought for about $10,000 but his best work can fetch close to $1 million in the US.

Last month's sale of prints and water colours at the Graham Arader Gallery in New York, one of only a few to specialise in botanical art, achieved total sales of $US6 million ($6.8 million). This shows the level of interest and the prices collectors are willing to pay for rare work, both old and new.

Another artist in demand is Maria Sybilla Merian (1647-1717), one of the few women to work in this field. A set of her original watercolours sold for $US800,000 at the Graham Arader sale. They had been bought for $US400,000 just five years before. Merian's work has just been exhibited at the J. Paul Getty Museum in Los Angeles, the first time an exclusively botanical exhibition has been held there. The show attracted record crowds.

While the likes of Redoute and Merian are beyond the reach of most of us, it is still possible to buy historical prints either as published in the original books or (more likely) removed and framed. In the case of Redoute, he developed his own exceptional printing techniques for his books. Single prints can still be bought from $600 for simpler ones and up to about $12,000 for the best. The first botanical books had woodblock prints, then engravings or original watercolours on vellum.

Australian Orchids, a series of more than 100 prints by Robert Fitzgerald, drawn between 1875 and 1882, are for sale at the Antique Print Room in Sydney's Queen Victoria Building, priced from $80 to $165 each.

Other Australian sources for prints and books include Gil Teague's Florilegium bookstore in Sydney and Brighton Antique Prints and Maps in Melbourne. Both dealers have a range of early prints for under $500.

On the other hand, something as rare as an original, complete copy of Robert J. Thornton's 1807 book New Illustration Of The Sexual Systems Of Carl von Linnaeus is likely to be held by major institutions. Original first editions are still available but rarely come on the open market. One is now for sale for $275,000. Single plates from books of this quality can sell from $500 up to $25,000 for the better plates.

Libraries are likely to be the bidders for these books, along with a handful of the world's great private collectors, such as the amazing Mrs Mellon, who has been accumulating her celebrated Oak Springs Flora collection in the US for nearly 80 years.

Much more accessible to new collectors are present-day books such as Dr Shirley Sherwood's Contemporary Botanical Artists. A first edition in hardcover format is a good investment as well as a valuable resource. Also recommended is Anne Marie Evans's An Approach To Botanical Painting, already hard to find in first edition.

Modern original artwork is also a good investment. The artists of the Botanical Art School of Melbourne have painted a collection of original paintings of the plants in Melbourne's Government House Garden, which they hope to publish as a limited-edition book. The artwork, known as a Florilegium, is being presented to the State Library of Victoria where it will be preserved and occasionally exhibited. The fact an artist's work is kept in a major institution adds to its potential value.

$200

This is from an 1810 reprint with copies of the original drawings but first editions of R.J. Thornton's New Illustration Of The Sexual System Of Carl von Linnaeus (1807) can be worth more than $250,000. Single prints from that book are worth up to $25,000.

$400

Copies of Pietro Matthioli's 1565 book, A Discourse On Plants - Scilla, are rare and increasingly valuable. Even a single page can be worth several hundred dollars.

$7500

John Evelyn's Silva - Or A Discourse On Forest Trees was published in the 18th century with illustrations by J. Miller. This is a fifth edition, printed in 1776. The book's conservation message is still relevant today.

My collection

Born in Boort, Victoria, Jenny Phillips studied at the Bendigo Teacher's College (now Latrobe University) before becoming a freelance botanical artist in 1971. She has been teaching since 1992 and founded the Botanical Art School of Melbourne in 1994. She also works as masterclass instructor at (among others) the Chelsea Physic Garden in London and the New York Botanical Gardens.

She recently contributed to volume one of Highgrove Florilegium and celebrated the launch of the book with Prince Charles.

"My intention was never to be a 'collector'," she says. "I purchased old botanical books and prints simply because I suddenly began to travel and had access to old works. I was fascinated in the story of the 'reasons' for botanic art - from very early herbals to gardening books - and now I find that many of those prints and books have become quite valuable."

As an example, on her travels she found some rare and cheap R.J. Thornton prints from his 1810 edition of Temple Of Flora at a street stall in Venice. Thornton prints can now fetch more than $50,000 each.

Her collection of historic prints is a source of inspiration but she says she is also aware that original contemporary botanical paintings are equally important so this tradition can continue.

"I would far prefer to collect original work from living artists," she says. "It's a fabulous way to form a basis of a worthwhile collection - at the same time you are perpetuating a highly skilled art form and building living artists."

The Botanical Art School of Melbourne is at 1A Shipley Street, South Yarra. See www.jennyphillips.org.