The book started out 20 years ago as a revision and updating of "In Gardens," but it has evolved into a very different, quite unique book. And big. When you pick it up, it feels like you're handling an unabridged dictionary. It's 9 by 12 inches, and more than 900 pages thick.

The original book was to have been developed by noted Hawai'i plant expert Horace Clay, who died before getting very far into it. The project was turned over to the formidable botanical duo of George Staples, longtime botanist at the Bishop Museum, and Derral Herbst, one of the co-authors of the "Manual of the Flowering Plants of Hawai'i."

They took it in a new direction.

"It's not 'In Gardens II,'" said Bishop Museum Press director Blair Collins.

Like Neal's book, which was last printed in 1968, it covers the plants people grow — the ones we keep in our gardens, that grow in our parks, along our streets, in our yards. But Neal went beyond that to include many plants found in natural areas, trees grown for reforestation, some weeds and pasture grasses.

"The scope of 'A Tropical Garden Flora' is narrower, with the focus on species deliberately cultivated indoors and in gardens. In addition to numerous ornamentals, coverage includes vegetables, herbs, fruits, nuts, shade and street trees, hedge plants, lawn grasses and ground covers, aquatic plants, and species suited for container culture on a lanai, patio, or balcony, or as bonsai specimens," the authors write in their introduction.

Where Neal included a great deal of legend and cultural tradition about plants known to the Polynesians, the new book's focus is more on modern cultural uses, including which ethnic groups use different plants.

And "A Tropical Garden Flora" includes detailed information on how to grow the plants. You learn whether to best propagate them from seeds, grafts, stem, root or leaf cuttings, or through other means. It discusses moisture and sun requirements, cautions about salt exposure, warns about susceptibility to rats and insects — that sort of thing.

It has extensive illustration, including nearly 500 line drawings by botanical illustrator Anna Stone, and 80 photographs of plants in a section of color plates. There's a healthy glossary, several pages of drawings that review different flower, fruit and leaf types and parts.

For folks baffled by scientific names, there is a guide to the derivation of those names. For example, citrinus refers not to the shape, smell or taste of citrus, but to the color lemon yellow. Macrophyllus means large leaves. And something named nealii is named after botanist Marie Neal.

One feature that follows Neal's book is an index that includes the scientific, Hawaiian and common names all in the same list.

The co-authors sought out world experts in specific plant families to help with the work and list more than 30 of them as contributing authors.

The volume does not claim to have every plant you'll find in the populated parts of the state. Herbst said the roughly 2,000 entries may represent only a fifth of that. But it covers the ones you're likely to come across.

And for many tropical areas of the world, it will be nearly as useful as it is in Hawai'i — both because many of the same species are cultivated throughout the tropics and subtropics, and because there really isn't another book like this one available. Collins said the museum press expects a fair proportion of foreign sales.

For the avid urban and rural plant lover and grower, this book will be a treasure. Although it's imposing, it is written for most of us — when the authors use the term "chlorosis," they add the word "yellowing" in parentheses.

For folks who seek out native plants and the back country, the two-volume "Manual of the Flowering Plants of Hawai'i" will continue to be the botanical bible — although it's written for the scientist and educated amateur.

And Herbst concedes that if you're interested in the myths and legends of the plants of the Islands, you'll also want to search out an old copy of Neal's "In Gardens of Hawai'i." The old classic still is.