© Cstaffa at English Wikipedia, some rights reserved (CC-BY) · Wikimedia Commons
Overview
Pterospora spp. is a genus in the heath family (Ericaceae) containing a single species, P. andromedea, known as pinedrops or giant bird's nest. It is a mycoheterotrophic plant that contains no chlorophyll and does not photosynthesize; instead it obtains all its carbon from soil fungi that are themselves linked to the roots of conifers. The plant appears as a single unbranched, reddish-brown to tan flowering stalk 12-40 inches (30-100 cm) tall, sticky with glandular hairs, rising directly from the forest floor with only scale-like bracts in place of leaves. Along the upper stem hang numerous urn-shaped, creamy white to pale yellow flowers about 0.3 inch (8 mm) long, resembling those of other heaths. After flowering the stalk dries to a rigid brown spike that can persist, holding rounded capsules full of tiny winged seeds. Pterospora spp. grows in the duff of coniferous and mixed forests across much of North America, with a disjunct population in Mexico. Because it depends on a precise fungus-and-conifer relationship, it cannot be transplanted or cultivated and survives only undisturbed in the wild.
Native Range
Pterospora andromedea is native to North America, occurring widely but sporadically across Canada and the United States, from the Pacific Northwest and California through the Rocky Mountains to the northeast, with a separate population in the mountains of Mexico. It grows in deep leaf-and-needle litter under conifers such as pine and fir.Suggested Uses
Pterospora spp. is not used in cultivation. It is encountered as a wildflower of conifer forests and is of interest for its mycoheterotrophic biology. It has been used in some regions as an indicator of established, undisturbed forest soils.How to Identify
Appearance
Size & Dimensions
Height1' - 3'4"
Width/Spread2" - 4"
Bloom Information
Flowering occurs in late spring and summer, generally June to August depending on elevation and region. The nodding urn-shaped flowers open along the upper stalk over a few weeks. The stalk then dries and releases seed from upright capsules.
Detailed Descriptions
Flower Description
creamy white to pale yellowFoliage Description
leafless (reddish-brown stem)Growing Conditions
Sun Requirements
Tolerates up to 3 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight