Among other sources from which rubber is commercially obtained may be mentioned the Guayule plant (Parthenium argentatum) of Mexico, and the "Ecanda " plant of Portuguese W.
Parthenium and Maenalus on E.
P. parthenium, pellitory or "feverfew," was formerly used in medicine.
Pyrethrum Parthenium aureum: half-hardy, I ft.; grown for its golden foliage, and much used for bedding.
P. Parthenium eximium, 2 ft., is a handsome double white form of ornamental character for the mixed border; P. uliginosum, 5 to 6 ft., has fine large, white, radiate flowers in October; P. Tchihatchewii, a close-growing, dense evergreen, creeping species, with long-stalked, white flower-heads, is adapted for covering slopes in lieu of turf, and for rockwork.