Desert Tea or California Ephedra (Ephedra californica) https://www.inaturalist.org/observations/10229653 by @thunefeld
and
Mormon Tea or Boundary Ephedra (Ephedra aspera) https://www.inaturalist.org/observations/9952923 by @efmer

Two species of Ephedra are fairly common in San Diego County's desert transition areas, Ephedra californica and Ephedra aspera. There are more voucher specimens in the SDNHM herbarium of E. aspera collected in San Diego County than there are of E. californica (105 vs. 82), but interestingly, there are more verified observations on iNat of E. californica than there are of E. aspera (49 vs. 26).

When you find an Ephedra bush in the field, it can be a challenge to decide which species it is. The two can look confusingly similar, especially in photos. But look carefully at the tiny leaves found at the joints on the stems of the plant and take a close-up photo that shows whether there are 2 or 3 leaves at each joint or node. The leaves are very small on both species, but E. californica has 3 leaves per node and E. aspera has 2 leaves per node. I remember this by associating the smaller number of leaves with the shorter specific name (2 goes with aspera) and the larger number of leaves with the longer specific name (3 goes with californica).

The observations of the month illustrate how you can distinguish between the two species. You won't find flowers on this gymnosperm to help sort out the species, but close attention to the tiny leaves will help you solve the puzzle of identification. If you are up for a challenge, look for E. californica in coastal San Diego County. There are several early 20th Century records but no recent voucher specimens or iNat observations close to the coast. Maybe you will be the first to find one!