Tufted Tackweed, Fremont's Calycadenia: Calycadenia fremontii (Synonym: Calycadenia ciliosa) -
Smooth Tackweed, Rosin Weed: Calycadenia truncata (Synonyms: Calycadenia truncata var. scabrella, Calycadenia truncata ssp. scabrella, Calycadenia truncata ssp. truncata) -