Table 1. Species of cover plants for saguaros in the census plots grouped into three classes.

Cover class	Scientific name	Common name	Saguaro count
C1	Parkinsonia microphylla	Foothill paloverde	403
	Prosopis velutina	Mesquite	99
	Condalia warnockii	Mexican crucillo	7
C2	Acacia (Vachellia) constricta	Whitethorn acacia	62
	Larrea tridentata	Creosote bush	46
	Acacia (Senegalia) greggii	Catclaw acacia	19
	Ephedra sp.	Mormon tea	11
	Other species		13
C3	Isocoma tenuisecta	Burroweed	79
	Zinnia acerosa	Desert zinnia	32
	Psilostrophe cooperi	Paperflower	12
	Grasses		17
	Other species		33
	open		31

Note: Cover classes: (C1) large trees; (C2) small trees or large shrubs; (C3) small shrubs, grass or plant with minimal or no cover. Saguaro counts include all new plants found under each species over the census period, 1942–2010.