A commonly used name for Hosta is plantain lily because the foliage is plantain-like and the flowers are lily-like. The Hosta is a genus from the Asparagaceae family and is native to open woodlands in Japan, Korea and eastern Russia.
Hostas are very popular because they grow well in the shade. It is also known that snails and slugs are fond of the leaves. If you want to keep the leaves looking nice you will have to take action against the slugs and snails.
You regularly see the word tetraploid when reading about Hostas. A tetraploid Hosta is a Hosta with 4 sets of chromosomes instead of 2 sets (diploid) which is most common. The tetraploid Hostas can occur spontaneously or can be made artificially with the help of chemicals.
The advantage of tetraploid Hostas is that the leaves are generally thicker which makes them firmer. That means that the leaves will stay upright better and are a bit more resistant to snails and slugs. Also the leaves can often better withstand the sun and are sometimes even prettier in it. Only by testing you can be sure if you have a tetraploid plant or not. The outer characteristics are definitely no guarantee.
Another word that is often used with Hostas is the word sport. A sport is a shoot of a plant that looks different than the original plant.
For the sizes of the Hostas I use the following heights:
> 30 inches (75 cm)
18 – 30 inches (45 – 75 cm)
10 – 18 inches (25 – 45 cm)
6 – 10 inches (15 – 25 cm)
< 6 inches (15 cm)