Montana Field Guide

DRAFT: Requesting feedback on the 2026 revised rank, factors, and State Rank Reason outlined below and in the Conservation Status Rank Report. Centunculus minimus is rare in Montana, being known from over a dozen, widely scattered sites in the state. At least 2 occurrences are large and appear to have good long-term viability. The species occurs in low elevation, vernally moist wetland and riparian habitats, which have been negatively impacted by development, agriculture, livestock and invasive species in the past. Actual trends are unknown, though it appears very likely that the species has declined or been extripated at some sites over the long-term as a result. Invasive species and climate change may negatively impact the species and its habitat in the future. Data for the majority of the sites is from the 1990's leading to uncertainty about its status. This uncertainty in conjunction with its overall rarity and potential threats appears to make the species vulnerable to extirpation. Surveys are needed at most of the known occurrences to document current population size, habitat quality and potential threats. Monitoring data are needed for at least several of the larger populations to determine potential trends. Additional surveys of potentially suitable habitat may locate additional populations.