Dore’s Needlegrass

Achnatherum nelsonii ssp. dorei, commonly known as Dore’s Needlegrass, is a perennial grass species native to the western United States, particularly found in the mountainous regions of the Rocky Mountains and adjacent foothills. Its distribution primarily spans parts of Wyoming, Montana, and Idaho, where it thrives in well-drained soils and is often found in grasslands, open forests, and disturbed areas. This subspecies typically exhibits a growth habit that reaches heights of 30 to 90 centimeters (approximately 12 to 35 inches), forming dense clumps that contribute to its overall tufted appearance.

The leaves of Dore’s Needlegrass are narrow, linear, and can grow up to 30 centimeters long, with a distinctive rolled or folded appearance that is characteristic of many needlegrasses. The flowering period occurs from late spring to early summer, producing inflorescences that are elongated and slender, with spikelets that are typically 4 to 8 millimeters long. These spikelets are arranged in loose, open panicles and are notable for their long awns, which can be several centimeters long, aiding in seed dispersal. The fruit, a caryopsis, is small and typically brownish, maturing in late summer.

Ecologically, Dore’s Needlegrass plays a significant role in its native habitats by providing forage for herbivores and contributing to soil stability through its fibrous root system. It is also an important component of the grassland ecosystem, supporting various insect species and acting as a cover for small mammals. In terms of human uses, this grass is occasionally utilized in restoration projects due to its adaptability to dry conditions and its ability to establish quickly in disturbed sites. An interesting adaptation of Achnatherum nelsonii ssp. dorei is its tolerance to drought, which allows it to survive in environments with limited water availability, making it a resilient species in its native range.