User:Purbendra Yogi/Hexalectris colemanii

Hexalectris colemanii
Hexalectris colemanii is an obligatory mycoheterotrophic (non-photosynthetic) species of the genus Hexalectris, also called Coleman’s carol roots. H. colemanii lacks chlorophyll and grows with fungi that are associated with the roots of other plant communities. The word Hexalectris comes from the Greek (hex, meaning six, and Alectryon, cock's-comb), referring to the six longitudinal crests found on its floral lip.

Description
H. colemanii differs from other orchid species in the size and color of the flowers and the shape and size of their labellum. H. colemanii has an underground rhizome, and only emerges above ground to blossom and propagate. Flowers can be self pollinating. There are 4-6 sheathing bracts on 40-55 cm pinkish-cream stems. The blooming stack ranges from pink to white, purple to pink striped petals, and maroon to purple striped sepals. It has a central lobe that is acute near the tip; petals that are 19-22 mm long, strongly revolute; and a column that is 14-15 mm long. H. colemanii typically flowers in May and August but may vary based on rainfall, temperature, or nutrient availability and locations.

Taxonomy
H. colemanii, originally discovered by Toolin and Reichenbacher in 1981, was mistakenly identified as H. spicata by those researchers. Further research led by Catling conclude that the Arizona plants differed from the Texas variety, and naming the Arizona variety H. revoluta var. colemanii in recognition of Ron Coleman, an expert on Arizona orchids who was the first to identify the unique traits of the Arizona orchid. Based on phylogenetic and morphological studies, Kennedy and Watson promoted H. colemanii to the species level in 2010.

Distribution and Habitat
There is a very restricted distribution for H. colemanii, which grows only on the roots of trees and shrubs in symbiotic associations with fungi. It is found in southeastern Arizona and southwestern New Mexico. In Arizona, including the Baboquivari, Dragoon, Piloncillo, Santa Rita, and Whetstone mountains. It was recently found in the Piloncillo’s Hidalgo County, New Mexico H. colemanii is reported to occur between 4,500- and 5,200-feet of elevation in canyon bottoms, on hillsides near canyon bottoms or among rocky outcrops associated with oak. H. colemanii is a rare species that is only found in few places.

Ecology
Because the orchid is totally dependent on its host, its rhizome coexists with a fungal symbiont, and the fungal hyphae serve as the plant's roots by absorbing water and nutrients. Molecular phylogenetic methods show that H. colemanii is commonly associated with the ectomycorrhizal fungal family of Sebacinaceae. H. colemanii rarely associated with members of the Ceratobasidiaceae. H. colemanii is a rare species, mostly threatened by fire, mining, animal grazing and trampling. . Field based US Forest Service classifies this species as a sensitive plant, and it was requested that it be protected under the endangered species act.