Participant Info

Species

Melilotus officinalis [Trifolium melilotus-officinalis]

Family

Fabaceae

CommonName

yellow sweetclover

Presence

YES

Status

exotic

EarliestDate

1915

LatestDate

2022

Ecosystem

basin, shrubland, foothill, montane, ruderal, urban

Geobotanical

SSawatch, Garitas, SSanjuans, NCristos, UBasin, LBasin

Counties

Alamosa, Conejos, Costilla, Hinsdale, Mineral, Rio Grande, Saguache, Archuleta

Passes

Wolf Creek

WildlifePreserves

Blanca Wetlands, Brown Lakes, Coller, Great Sand Dunes, Russell Lakes, Terrace Reservoir

Other Localities

Alamosa (town), La Botica, Del Norte

PhotoRecords

YES Rich Haswell: Alamosa Co, Blanca Wetlands N of Alamosa 18 Sept 2020; Nick Moore: Saguache Co, Russell Lakes WPA 17 July 2022 (iNaturalist observation 127148431)

Comments

In late summer yellow sweetclover, an exotic from Eurasia, lines the roads, streets, and highways of the Watershed (e.g., Hwy 160, Hwy 17) and sometimes spreads into neighboring fields and meadows. Lately in the town of Del Norte (Rio Grande Co)—2024-2025—it has spread observably along alleys and streets. Note that the species has long roots that can penetrate the densest substrate. The largest plants Hulk Hogan couldn't pull up. Meliotus officinale has been recorded from the Watershed for a century (and in Colorado since 1890). It now grows in every state of the USA, and follows the Rio Grande drainage from the Watershed to the Gulf of Mexico. In the Watershed, it deserves the epithet "invasive." Yet so far (Aug 2025) it is not designated as "noxious" in Colorado.

Annotation