| Scales of the broad and flat involucre imbricated, with scarious margins. |
| Stipules not scarious, leaves palmately cleft or palmately compound. |
| However, the sterile lemmas are only half the length of spikelets, linear and scarious, whereas sterile lemmas are wide, coriaceous and the same length as the spikelets in O. grandiglumis. |
| Scales of the involucre dry and scarious, white or colored, imbricated in several rows. |
| Receptacle convex to subulate, chaffy, the scarious chaff not embracing the smooth dorsally compressed achenes. |
| A polymorphous plant, with larger, more globose and racemose heads, and more scarious involucres than any form of A. vulgaris. |
