Left, an example of C. luteus from San Mateo County; right, a Santa Clara County flower.
The Yellow Mariposa Lily is another quite common Calochortus species--examples can be found in almost every California county. It tends to be rather short in the wild--about 9-12 inches, but in optimum conditions under cultivation, it can grow as high as 17 inches. It's flowers too, are not as deep or broad as other Mariposa Lilies--usually just over an inch across. What it lacks in stature, however, it makes up for in fertility: it is often found in abundant clusters in open meadows and grassy areas under full exposure to the sun.
In cultivation, C. luteus is perhaps the easiest Calochortus to grow from seed, sprouting earlier and growing faster than its cousins C. venustus and superbus. It has also been rumoured to reach flowering maturity in two growing seasons, but it's been our experience that it takes three.
Some cultivated C. luteus seed pods in the process of drying out. The one splitting open is actually 1 5/8 inches long.