Orchidaceae
Aa
Kingdom: Plantae Rank: Genus Parent: Orchidaceae Status: Invalid Reason: unverified
Morphological Description
Diagnosis: Plants of Aa do not resemble orchids at first glance and can be casually mistaken for other groups such as Plantago (Plantaginaceae). The small, globose flowers are densely clustered on the rachis. The flowers are mostly formed by balloon-like lips with minutely fringed margins. The only similar orchid in the region is Myrosmodes which differs by having extremely short inflorescences at soil level. Plants of Myrosmodes inhabit swampy habitats while those of Aa grow in mesic areas. Plants of Aa do not appear to be affected by disturbance and are commonly found along dry roadsides and along trails at Inca ruins.
Vegetative Morphology
Habit: Rosulate terrestrials with fasciculate, fleshy, pilose roots.
Leaves: Leaves oblong-elliptic, developing fully after flowering.
Reproductive Morphology
Inflorescence: Inflorescences lateral, stiffly erect, pedunculate, densely-flowered racemes, the floral bracts typically exceeding the flowers.
Flowers: Flowers minute, not resupinate. Sepals and petals free, the dorsal sepal and petals with recurved apices, the lateral sepals parallel with the lip. Lip unlobed, balloon-like with incurved, fimbriate margins, with a pair of subglobose calli at the base. Column very short, with a truncate rostellum; pollinia four, sessile.
Other
Notes: Norma Salinas (pers. comm.) indicates that more species of Aa are present at Machu Picchu than have been recorded in the literature. The genus is in need of revision in the region and all determinations should be taken as tentative at this time.