Where can I get some Hygrow plant?

There's a couple of different hygros, the most common is probably hygrophila difformis (wisteria). Under bright light, it grows like a weed. I have some in a 12 gallon tank with 2.5wpg, and it overtook the tank in less than 2 weeks. Most LFS that sells plants should have some, and they're very cheap online too.

Wisteria does not have bulbs. It is a stem plant. With its rapid growth it is great for using up nitrates. I'm not sure of the recommended lighting requirements but mine is growing like mad with less than 1WPG.

No, and technically, yes.

I had wisteria before under my ten gallon with a 28 watt, but it turned brown and rotted in the water. I don't know why though.

It's a really pretty plant if you can grow it. I heard it is a hardy plant, but when I had it, it died.

Actually my Wisteria does not grow quickly at all. I have it under 15W in a 5Gal and 28Watts in a 10gal. It's a nice slow grower under low-medium light that stays very healthy if given enough nutrients.

The fast grower is Hyrophilia Polysperma (green or sunset). This plant has been banned in several states as a Noxious weed (fortunately not Wisconsin). It grows three to four inches per week in my 10gal and about an inch per week in my 5gal. It is great at keeping excess nutrients in check and out competing algae. When it gets too long I just take my shears, grab a bunch of stems under water, and snip them level about half way down. Unlike Wisteria the leaves are large and broad and the stems are easy to grab so you don't end up with such a mess in the tank, just a few stray leaves to pick up.

If you can't find any near you let me know and I will mail you some clippings. I have polysperma and wisteria.