Allium bisceptrum, commonly known as the twincrest onion or aspen onion, is a perennial herb native to the mountainous regions of the western United States, particularly in subalpine and alpine zones. It is found in moist meadows, open woodlands, and along streams at elevations ranging from 6562 to 9514 feet. The plant typically forms round, egg-shaped bulbs that emit a strong odor when disturbed. The twincrest onion produces two to four long, flat leaves that are often paired and release an onion-like fragrance when scratched. During the flowering season, which occurs in late spring to early summer, it bears umbels of star-shaped flowers that are usually purple or pink, adding a splash of color to its native habitats.

In cultivation, Allium bisceptrum is valued for its ornamental flowers and its use as a culinary herb, providing a distinctive onion flavor. It is suitable for rock gardens, borders, and naturalized areas, particularly in settings that mimic its native alpine conditions. This plant prefers well-drained soils, consistent moisture, and can tolerate partial shade, although it will flourish in full sun. While it is not commonly found in cultivation, it can be an interesting addition to a garden that accommodates its specific growing conditions. It is also important for supporting pollinators such as bees. Potential problems include bulb rot if grown in poorly drained soils and susceptibility to onion thrips.CC BY-SA 4.0