First two pics show two species for comparative purposes.
Specimen on right: Note V-shaped base of flower, less dense branching, longer/narrower petals compared to Amphiachris (left; https://www.inaturalist.org/observations/34926032).
These specimens were growing adjacent to one another in the same soil type (a silty, firm sandy loam).
I'd like to thank the Home Depot Corporation for being cool with me hopping the fence without permission to come scope out this awesome dry land limestone prairie.
Ray and disc florets of this species with the fruit in the background. Photos taken by Sonnia Fajardo Hill.