Piperia transversa, the Flat-spurred Piperia is a smaller plant with small but unusual flowers. It's name refers to the position rather than the shape of the spur, and as one writer says, it would better be called the "horizontal-spurred" Piperia. The position of the spur is also the key to identifying this species which otherwise resembles the Long-spurred Piperia (Piperia elongata) both in flower and plant size.
The plants grow to about 60 cm tall, though many of them are smaller, and the individual flowers are 1.5 cm to the tip of the spur. The leaves, which lie close to the ground, are usually gone by flowering time, so that the flower spikes appear to belong to a leafless plant. The plant is native only to the Pacific Northwest and ranges from British Columbia to California.
The plant grows in open areas in woodlands often in very mossy areas, sometimes hidden by the surrounding vegetation, and is often found alongside the Giant Rattlesnake Orchis, Goodyera oblongifolia, though that plant blooms later. The flower spikes where we have seen them are usually scattered, not in clumps, and the plant from in our area from mid-July into August.
The flowers are white with a greenish stripe down the center of the segments and the spur is also tipped with green. The nectar is visible in the spurs when the flowers are examined closely, and the flowers are said to have a clove-like scent at night, though we have seen them only in the day-time and could detect no scent. They can number up to 100 per spike.