Both Baileya multiradiata and B. pleniradiata produce an antineoplastic pseudoguaianolide, radiatin, which might prove useful in cancer therapy (J. J. Einck et al. 1978). In addition, the antibiotic sesquiterpene lactone, baileyolin, from B. multiradiata inhibits tumor formation (X. A. Dominguez et al. 1977).
Baileya multiradiata is reportedly toxic to livestock, especially to sheep and goats, where losses as high as 25% have been reported on overgrazed rangeland in Texas (D. W. Hill et al. 1979, 1980). Cattle and horses seem to be unaffected, or at least poisoning of these animals has gone unreported. The chemical agent responsible is believed to be hymenoxon, a sesquiterpene lactone originally found in the genus Hymenoxys, where it is also toxic.
The poorly known desert marigold moth, Schinia minima (Grote), appears to be endemic on Baileya multiradiata, using the heads of this species for its larval development (T. G. Myles and B. F. Binder 1990).
The autumnal blossoms of Baileya multiradiata, with smaller heads, fewer rays, and shorter peduncles, greatly resemble those of B. pleniradiata. This has caused much confusion in the distinction between these two species. The shape of the style apex is a useful character to distinguish between fall-blooming specimens.
