Regarding Calochortus monophylus bright yellow with and without brown basal mark, I have seen them both in the field at Table Mountain near Chico. They are both blooming in a pot here in Ukiah for a number of years with no Cal. albus nearby. Regarding a cross between Cal. monophylus and C. albus in nature, it has been recognized for many years. Stan Farwig, the Calochortus guru, told me about it. The cross looks like Nhu's picture, pale lemon, half open and fuzzy. Interestingly, the natural cross between Cal. amabilis and C. tolmei looks just about the same. I have had four of them blooming for a number of years and they are blooming now on the hillside by my home. How come? 25 years ago I fenced out the deer from a one acre area around my house on a wooded hillside. Amazingly, Calochortus amabilis and short little whie C. tolmei and Frit. amabilis came out of hiding. They are now in large colonies while outside the fence there is nary a one that doesn't get browsed off. In the areas where C. amabilis and C. tolmei abut and overlap is where the crosses occur. They are midway in heght between the two and look droopy. They set seed poorly. I planted 3 seeds one year,but they didn't sprout. I will send Mary Sue recent pictures. Bob Werra