Pterospora

Pterospora
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Ericales
Family: Ericaceae
Subfamily: Monotropoideae
Genus: Pterospora
Nutt.
Species: P. andromedea
Binomial name
Pterospora andromedea
Nutt.

Pterospora, commonly known as pinedrops, Albany beechdrops, or giant bird's nest is a monotypic genus in the subfamily Monotropoidiae of the blueberry family, the Ericaceae, and includes only the species Pterospora andromedea.[1] It grows in coniferous or mixed forests. It is native to North America from southern Canada to the mountains of Mexico and is most commonly found in the western half of the continent, though small isolated populations are found in the northeastern United States and eastern Canada. Along with Monotropa it is one of the more frequently encountered members of the Monotropoidiae.[2]

The fruits are five-celled woody capsules (Wenatchee Mountains, Washington).

The genus name is derived from the morphology of the seeds which have narrow flaps of tissue on the side and therefore appear winged: ptero (Gr.) = winged, spora (Gr.) = seed. The specific name andromedea derives from the resemblance of the flowers to those of another genus in the Ericaceae, Andromeda.[2]

The visible portion of Pterospora andromedea is a fleshy, unbranched, reddish to yellowish flower spike (raceme) 30-100 cm in height, though it has been reported to occasionally attain a height of 2 meters. The above-ground stalks (inflorescences) are usually found in small clusters between June and August. The inflorescences are hairy and noticeably sticky to the touch. This is caused by the presence of hairs which exude a sticky substance (glandular hairs). The inflorescences are covered by scale-like structures known as bracts. The upper portion of the inflorescence has a series of yellowish, urn-shaped flowers that face downward. [3] The fruit is a capsule.

Like all members of the Monotriopoidiae (see Monotropa), Pterospora andromedea lacks chlorophyll (trace amounts have been identified, but not enough to provide energy for the plant or to color it).[4] Plants exist for most of their life as a mass of brittle, but fleshy, roots. They live in a parasitic relationship with mycorrhizal fungi, in which plants derive all their carbon from their associated fungus, but the relationship is not yet well understood. The term for this kind of symbiosis is mycoheterotrophy. In Pteropspora the association is with a very limited number of fungi in the genus Rhizopogon, including Rhizopogon subcaerulescens, R. arctostaphyli, and R. salebrosus. A note of caution: unlike plants, fungi are not yet well categorized and so species' names are likely to change frequently as more research is done and Rhizopogon is particularly hard to taxonomically categorize. Pterospora has yet to be discovered with any species outside the genus Rhizopogon. [5]

Pterospora has consistently been shown to be more closely related to Sarcodes than any other member of the Monotropoidiae. [5]

See also

References

  1. ↑ "USDA: Pterospora andromedea Nutt.". Retrieved 2008-08-15.
  2. ↑ 2.0 2.1 Wallace, G.D. (1975), Studies of the Monotropoidiae (Ericaceae): taxonomy and distribution, The Wassman Journal of Biology
  3. ↑ "MSU: Pterospora andromedea Nutt.". Retrieved 2008-08-15.
  4. ↑ Cummings, Michael P.; Welschmeyer, Nicholas A. (1998), Pigment composition of putatively achlorophyllous angiosperms, Plant Systematics and Evolution
  5. ↑ 5.0 5.1 Bidartondo, M.I.; Bruns, T.D. (2001), Extreme specificity in epiparasitic Monotropoidiae (Ericaceae): widespread phylogenetic and geographical structure, Molecular Ecology

External links