These days, Castilleja is in the Orobanchaceae family, but in Arizona Flora it is in the Scrophulareiaceae.
The Scrophulariaceae key is on page 762.
Anther bearing stamens 5, or otherwise? I see 2, no 4. Are the lower or upper corolla lobes external in the bud? The lower wrap around the upper, so lower. Upper corolla lobes arched forming a galea enclosing the stamens? Yes. Anther cells equal or unequal? Unequal -- and leaves are alternate. Calyx 1 or 2 lobed? 2 lobes. Upper corolla lip (galea) much longer that lower. Yes - Castilleja (21).Much of the above is very tricky -- but any numbskull would know it was Castilleja and would not bother with any of the above at all, and these days might be dealing with an Orobanchaceae key anyhow. I have to say that my Anther sacks all look the same to me, but they are all stuck together. Fresher material might help. Castilleja key on page 787.
Plants annual or perennial? Perennial. Bracts brightly colored? Yes. Bracts entire or toothed? Mine are mildly toothed, so I vote "entire". Corolla 3-4 cm or shorter? Shorter, mine are barely 2 cm. Stems whitish tomentose or lanate? No. Leaves thick and rigid or thin? Thin -- C. austromontana
Is the plant green or otherwise? Green (not a holoparasite) Leaves alternate or opposite? Alternate Tip of upper two corolla tubes forms a beak or hood? Beak Anther sacks 2 per stamen -- Castilleja.I don't see any of Arizona species in the California list, but I heard someone say that in the west, every mountain has its own species of Castilleja, and perhaps that is true.
Tom's Plant pages / tom@mmto.org