Yadon’s piperia was recognized as a distinct species in 1990 by the well-known local botanist Randy Morgan and an orchid biologist named James Ackerman. It was listed as federally endangered in 1998. This species of orchid occurs in Monterey County and nowhere else. It grows in two seemingly very different habitats: the maritime chaparral, like we find at Manzanita Park, and the Monterey Pine forest on the Monterey peninsula.

Yadon’s piperia is a perennial that grows from a small underground tuber. Each year, with the onset of the winter rains, a tuber can do 1 of 3 things. It can send up 1-2 strap-shaped leaves; it can remain alive but dormant underground; or it can die. The proportion of plants that remain dormant each year is highly variable. Tubers that send up leaves can either flower or die back and remain dormant for the rest of the year. As few as approximately 1% to 10% of the plants that leaf out actually bloom each year, with great variation between years. The fact that not all living plants emerge every year makes it very difficult to know how many individuals are growing in Manzanita Park and to track changes in population size from year to year. One estimate of population size for Yadon’s piperia in the Park was made by Dave Allen, who counted 3, 080 individuals in leaf in 1996.

The flowering stalk is leafless and from 4 to almost 32 inches tall; the plants found in the maritime chaparral are shorter than those growing in the Monterey pine forest. An average of 56 flowers occur on any one plant. The flowers have a short downward-curving spur that contains nectar. The flowers appear to be pollinated primarily by night-flying moths that drink the nectar. The flowers develop a somewhat spicy scent at night that presumably attracts the moths. Bumblebees may serve as day-flying pollinators.

This species was listed as federally endangered due to several threats to its persistence. The largest threat is continued residential and recreational development. The natural habitat of the species has largely been developed and what is left is highly fragmented, so that the remaining plants occur in relatively few and often small patches. Deer pose a threat because they like to eat the flowering stalks, which prevents seed formation. Competition from non-native invasive plant species (such as the jubata grass, French broom, ice plant, and Eucalyptus that occur in Manzanita Park) is another large threat. Fire suppression may also be contributing to the loss of high quality habitat for Yadon’s piperia, since the maritime chaparral and Monterey pine forest are both fire-adapted communities. Fires help maintain the low-growing manzanitas that Yadon’s piperia is associated with in the maritime chaparral and the grassy and open forest floor that it enjoys in the Monterey pine forest.

This orchid may soon be placed in another genus of orchids, Platanthera. If this happens, its name will change to Platanthera yadonii, but it will still receive protection under the Federal Endangered Species Act.

Yadon’s piperia is a perennial that grows from a small underground tuber. Each year, with the onset of the winter rains, some of the tubers send up 1-2 strap-shaped leaves. These pictures of piperia were taken in February and March. Piperia in Manzanita Park are often found at the edge of low growing Hooker’s Manzanita.

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However, piperia can also be found on sandstone formations. The piperia in the sandstone areas receive less water and are generally smaller in size. Some of the plants grow on or close to areas where people walk.

Around April, the piperia send up flower stalks. The flowering stalk is leafless and from 4 to almost 32 inches tall. The plants found in the maritime chaparral habitat are shorter than those growing in the Monterey pine forest. Once the flowering stalks begin to appear, the leaves start to wither and dry up.

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In May and early June, the white flowers on the Yadon’s piperia begin to be noticeable. It is at this time that Yadon’s piperia can be distinguished from other piperias, such as the Piperia elongata, or Dense-flowered Rein Orchid, because Piperia elongata have green flowers. By the time the piperia have reached this point, the plants that didn’t flower this year have all but disappeared.

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From mid-June through July, the Yadon’s piperia flowers continue to open up along the flower stalk from the bottom to the top. An average of 56 flowers occur on any one plant. This is when the plants are easiest to find because the white flowers contrast with their surroundings.

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In August, the flowers give way to fruit. Orchids do not produce seeds, but a fine dust instead. This dust depends on a symbiotic relationship with fungi in the soil to sustain the orchid until it can form an underground tuber that can store energy. One of these pictures has two stalks, a flowering stalk from the current year and another dry spent stalk from the previous year.

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