Dick and John,
If you look closely at the first few pics, you'll see that the 'native' grasses are in fact growing out of the lava beds. The grasses weren't planted there, they were already there, just like at nearby Mauna Kea. Mauna Kea used to look like Mauna Lani, etc. with all of the black lava, but over the years (course is 35+ years old) grasses started to grow there.
No matter if the grasses were there or not, you certainly couldn't play from there regardless. The grasses look better than lava, IMO and you might get an occasional hittable lie.