Not exactly what you're looking for, but "Handbook of Hawaiian Weeds" by E. L. Haselwood, G. G. Motter is a great resource now available for free download as a PDF.
http://scholarspace.manoa.hawaii.edu/bit...sequence=1
clicking on link downloads the pdf onto your computer, does not open a new page.
You can also borrow a paper copy from the library, or pay $50+ for your very own copy.
The book features line drawings of the plants, sorted by type (grasses, composites, etc.) A section at the back explains the botanical terms they use so you can describe and search for a plant.
I've used it to identify a few weeds around here, notably Kosters Curse, possibly the best weed name ever. Sadly, it doesn't tell us who Koster was, or if he was cursed with this plant or he cursed us with it.
MELASTOMATACEAE (MELASTOMA FAMILY)
Clidemia hirta (L.) D. Don
Synonym: Melastoma hirta L.
CLiDEMIA, KOSTERS CURSE
Description:
A branching shrub, 3 to 6 feet high, densely hairy throughout.
Leaves papery, hairy on both sides, 4 inches long, broadovate,
mere or less indented at the base, with five to seven
veins spreading from the base. Flowers white, 1/2 inch
across, clustered in the upper leaf axi I s, 5- to 6-parted.
Fruit a fleshy berry, small, black, hairy, edible (15, 16).
Propagation:
By seed.
Habitat:
Adapted to moist conditions. Found in the forest reserve
above Wahiawa, Oahu. A potential weed in waste places,
pastures, and rangel and s.
Hi story:
Native to tropical America. First noted on Oahu in 1952.
Notes:
Declared noxious in Regulations 2 and NW 10. Of no
forage value. Grows fast and quickly takes over an area.
Lee's note: now found all over Hawaiian Acres, probably in your area, too!