The fosterianum clade comprises six pedunculate species (O.
alvimii, O. fosterianum, O. grossiorum, O. gurkenii, O. lanuginosum,
O. magalhaesii) with inflorescences in lax spikes of spikes, and
leaves and primary bracts with lepidote-lanate indumentum, the
latter representing the morphological synapomorphy of the group