Using the Jepson eFlora Key to Githopsis, and the very detailed revision of the genus in Morin(1983), my best assessment for the ID here is Githopsis diffusa ssp. robusta.
Note that the hypanthium tubes appear narrowly-obconic to cylindrical, somewhat (very subtly) constricted near the middle, unconstricted at the apex, and slightly swollen at the base. The hypanthia also appear to have longitudinal ribs that are unequal in width & relief (cf. key and descriptions of specularioides and diffusa in Morin(1982)). Also, the length-to-width ratio for the hypanthia here ranges from 2-3 (consistent with subspecies robusta); and the length-to-width ratio for the hypanthia lobes (= “sepals”) here ranges from 3-6 (vs. around 10 for G. specularioides per pg. 459 of Morin(1982)).