A couple of new woods for your perusal. Any guesses?
The C,D set has a brass ring around the lower end of the mouthpiece, but the Delrin goes all the way the the top of the window, on the inside. It gives it a stiff upper lip.
Thanks for looking. No prizes for correct guesses, other than glory.
I shall be the first to look the fool. 
I’ll guess persimmon for the top picture and koa for the bottom.
The bottom picture looks like Palm wood.
It’s a bit hard to tell from the pic, but #1 looks a bit like machined bamboo.
If it’s not, you might want to try it-- makes a very handsome whistle.
Paul is right- the top one is bamboo, which is technically a grass, not wood.
Here’s a hint for the other: It’s a kind of wood whose name suggests it’s not wood.
The other wood looks a bit like beech, but then the name beech implies wood. Hmmmm… 
Ironwood?
Knotwood. 
That’s a bingo for CT- ironwood it is. And it sounds especially good. I’m going to have to try to find out if the brass ring at the bottom of the mouthpiece has the effect of reducing the vibration of the thin Delrin I use for a mouthpiece, thereby improving the flow of the airstream or maybe ironwood just makes a great whistle. I meant the extra brass to be decorative, but we’ll see.
Which ironwood? There are a whole bunch of unrelated trees that called by that name. The Australians have one, Canadians (or maybe eastern north Americans) have two (both Shagbark Hickery & Blue Beech get called ironwood), and IIRC there’s at least one other species in Africa that’s also known locally as ironwood.
what does the bamboo whistle sound like? That’s interesting stuff.
Sure, go all technical on me, S1m0n. The man said it’s a bingo. Just let it go! 
David makes very fine whistles. I have a blackwood C/D Rover set that goes everywhere with me. It takes a bit more control than my ‘easy’ whistles, but the payoff is there in spades.
Lovely stuff, David! 
I’ll tell you all I know about the wood I used: It was a 3 inch square by 17 inch fully waxed block labelled “Black Ironwood”. There are two types of this, according to Wikipedia. North American is not used for woodworking. It is an ornamental shrub. The other is from South Africa. It is supposed to have a specific gravity of 1.49. Mine floats with about 10% of the block above water, so it’s specific gravity is about 0.9. So I don’t really know exactly what type of blackwood I have.
I emailed the vendor of the wood to see if he has any other information. I’ll keep you posted.
The bamboo whistle sounds very good, for a low density material. I would call it “frisky”. I’m not surprized- bamboo has a few years of history as a suitable wood for flutes and whistles.
While American Hornbeam/Ironwood (Carpinus caroliniana) is listed as a shrub (or ornamental shrub), I recall it growing wild in the New Jersey area at 20–30 feet in height and a trunk diameter at chest height of 6 - 8". Don’t know if this is what you got but that size shrub/tree (when does a shrub become a tree? Do trees have puberty?) might yield a block of the size you mention. I remember is as being pretty hard for carving but didn’t try to float it…
Best wishes.
Steve
I received a fast reply to my email about the origin of the ironwood:
Hi David,
I got the wood from my supplier in the Kwazula-Natal area of South Africa.
Carpinus caroliniana isn’t the only North American “ironwood”. There’s also Ostrya virginiana, aka hophornbeam, aka ironwood. I’d be surprised if there weren’t others, as well. (And I can tell you that 100-year-old hophornbeam “ironwood” makes very nice whistles. I have two of them that Paul Busman made for me. )
The wood I used was labelled “Black Ironwood”. My cursory research only turned up two “black” types, but lots of different ironwoods.