Navarretia squarrosa Navarretia squarrosa seeds in a 1/4 tsp (2 cm diameter). Navarretia squarrosa seedlings germinated within a growth chamber set at a 25/15°C (77/59°F) day/night temperature with a 12-hour day photoperiod of cool-white fluorescent light. Navarretia squarrosa seedlings growing in 48-cell liners at the Berry Seed Bank research greenhouse located in Portland, Oregon. Navarretia squarrosa seedlings growing in 48-cell liners at the Berry Seed Bank research greenhouse in Portland, Oregon. Navarretia squarrosa rootball for seedlings growing in 48-cell liners at the Berry Seed Bank research greenhouse in Portland, Oregon. Navarretia squarrosa trichomes. Navarretia squarrosa leaves. Navarretia squarrosa flower.