"Common Hawaiian Trees," Friends of Hawai'i's Urban Forest, 2004, $16.95.

"Common Hawaiian Trees" is a beautiful little book with reproductions of native-plant paintings done by Isabella Sinclair in the late 1800s.

Hawaiian Electric helped support the book, along with Kaulunani, the state Department of Land and Natural Resources urban forestry program, the U.S. Department of Agriculture Forest Service and the Urban Garden Center.

It contains details on trees appropriate for planting in the urban environment that have been given away as part of Arbor Day programs in Honolulu since 1993. The book provides such valuable information as how tall the trees grow, how wide they spread and what kinds of soil they like.

Hawaiian Electric's interest is that people know the possible impact of specific trees on power lines.

"Kaua'i's Geologic History," by Chuck Blay and Robert Siemers, 2004, TEOK Investigations, $15.

Chuck Blay is a geologist who provides educational tours on the geology of several of the Hawaiian Islands; Rob Siemers is a map-maker. They have collaborated to produce a colorful, easy-to-understand guide to Hawaiian geology, focusing on Kaua'i, but with a great deal of information on the entire chain.

Kaua'i is the oldest of the main Hawaiian Islands, although the archipelago continues with older rocky islands and atolls of the Northwestern Hawaiian Islands, and beyond them, the submerged Emperor Seamounts.

On Kaua'i, a hiker can walk on prehistoric sand dunes and volcanic debris fields, on lava half a million years old, and on decomposed rock from eruptions 5 million years ago. The most recent eruptions, hundreds of thousands of years ago, were likely near the southern point of the island.

Factoid: The walls of the west side of Waimea Canyon are about 1 million years older than the east side. The book explains how that happened.

"Kaua'i Visitors Atlas," by Robert Siemers, 2004, Environmental Designs-Hawai'i, $6.

Siemers has produced one of the most fact-rich maps available in the state. In addition to standard roads, its main map includes surf spots, diving areas, botanical gardens, hiking trails, hotels, police and fire stations, and a great deal more. On the flip side, the atlas has major archaeological sites, translations of Hawaiian place names and data on climate and geology.