Which is in the grass family, Pachypodium or Arrhenatherum?
Arrhenatherum Arrhenatherum, commonly called oatgrass or button-grass, is a genus of Eurasian and North African plants in grass family.
Pachypodium ambongense Pachypodium ambongense belongs to the dogbane family Apocynaceae, which has recently been merged with the milkweed family Asclepiadaceae. It was first published as a species of the genus "Pachypodium" in 1924 by the botanist Henri Louis Poisson.