GardenWeb has a Hibiscus forum. Labeled specimens of various hibiscus can also be seen in local arboretums, botanical gardens and parks. There will surely also be some sort of local Hibiscus Society chapter or other enthusiast group available to you there.

American Hibiscus Society has a web site up.

Dave - how are you starting your cuttings ? Please give a short tutorial. Just stick the cutting in water ? I'm still trying to get up to see you - how's the butterfly thing going ? I've got some varigated ginger, and blue ginger and a small firecracker red kind I can share when I come - you need any ?

Thanks bboy! I didn't even think about going to the Hib. forum direct, LoL. Will do and see what I can come up with!

Hey there Pueokai,
Sorry in advance for the short note, I'll hop on a little bit later and post how I start all of my cuttings, have had plenty of success, maybe there are better ways, but if there are I haven't read or heard about them! Headin out the door, lol.
No worries, I've been pretty busy lately, I'll email ya later on and letcha' know what's up. I'm still all for the butterfly projects, just slow to get going and plenty of things to do right now, heheheh. I'd love some of the ginger, any and all ya've got for trade! I've actually been looking for some of the Blue Ginger for a buddy on the mainland, so that's a definite "yes", lol. Ah well, I'll hit you up later and fill ya in on everything, take it light 'til then, mahalo and aloha!

~Dave

Alrighty, here's how I grow my Hibiscus from cuttings, learned doing some nursery work on Kauai and plenty of research online.

I take cuttings of almost any size, but have found that 6"-1' work best. If it's a fresh cut, all the better. I scarify (cut, scrape, etc.) the base of the cutting, I do this about 1/4 to 1/3 of the way up the stalk from the base. I apply a dusting of rooting hormone to the damaged section of the cutting and then allow it to dry over. I mix 1/3 sand, 1/3 perlite, and 1/3 potting mix for the growing medium; this gives it good drainage, and the sand and soil will compact down to help hold the cutting in place while it roots. You can also leave about 1/2-1 inch of room between the soil-line and the rim to fill with pebbles or small gravel, will help hold your cutting in place. I can't tell you how many times I had something rooting like a champ and it gets knocked down and killed...LoL. A month or more of work down the drain =p If it's a larger cutting, I put them in a dappled light to partial sun part of the yard, and water when it's dry. I see results in 5-8 weeks on average, meaning a root pokes through the bottom or a new leaf forms. I use the black planters to help keep the cutting, and eventually the roots, warm to aid with the growth and development. Once I see there are indeed some roots, I give it a light application of Bonemeal or calcium to further aid in the process.
I've rooted anything from 3" long bare sticks, to 4' long branches full of leaves, but it seems to take the least amount of time using the medium sized, hardwood cuttings, with some leaves. Cut any leaves that are left on the trimming in half and allow them to dry over, this way the plant doesn't lose as much moisture when the leaves begin to die and rot or fall away. This can make a mess too, encouraging mold and bacteria to grow in the soil. The rooting hormone also has an anti-fungal/bacterial agent in it, which helps repel and/or kill anything that grows which would otherwise rot the cutting before it roots. Some plants, such as the Gardenia, I have read need to be grown from soft-wood cuttings, (trying this out for myself) meaning the newer growth which has not yet turned to wood, but is not so soft that it wilts after being cut. A good way to find some is to bend the green/brown new growth, if it snaps when you get to about 90 degrees, it's good to go! Also, for these tender plants, the smaller the cutting, the easier it is to root. Puakenikeni is the same way, I HAVE rooted 8" cuttings, though it says online that the mortality rate is too high to bother with it, I belive it was over 80% on average. But after reading that, I tried and succeeded in rooting 6 out of 10 cuttings. Wasn't too bad for me =] If you can't work with the airlayering, cuttings are a good way to go.

I'm no expert, but I've rooted plenty of things, and most often you can find out what part of the plant is best to root just by looking it up online. Hope this helps ya out some, again I'm no botanist, but this is from personal experience !

Aloha!
~Dave

The only thing I know, or noticed, is that the Hawaiian species I've seen tend to have round-scerated leaf margines.