Galinsoga semicalva (A. Gray) H. St. John & D. White

Plants 4–35 cm. Leaf blades lance-olate to ovate, 7–55(–80) × 3–20 mm, margins usually entire or serrulate, sometimes serrate. Arrays of heads congested. Axillary peduncles shorter than subtending bractlets. 2n = 32.

Flowering summer–fall. Rocky slopes; 1800–2700 m; Ariz., N. Mex., Tex.; Mexico.

Plants of var. semicalva are less branched and usually have narrower leaves and shorter axillary peduncles than those of var. parviflora. They are found above 1500 m as far south as Distrito Federal, Mexico. Morphologic intermediates between the diploid var. parviflora and the tetraploid var. semicalva occur throughout the range of var. semicalva.