Comparative anatomy of Sirhookera (Orchidaceae) growing in Western Ghats of Southern India

We compared the anatomical characteristics of vegetative organs, peduncle and mycorrhizal morphology of Sirhookera belonging to the subfamily Epidendroideae (Orchidaceae) to identify the anatomical markers for identification of Sirhookera species as well as to their ecological adaptations. The leaves are hypostomatic bearing tetracytic stomata and the walls of subsidiary cells are smooth in Sirhookera lanceolata and undulate in Sirhookera latifolia. The leaves on the adaxial and abaxial surfaces are covered by thick cuticle. The hypodermis is dimorphic and present on both sides of the leaf; chlorenchyma is homogenous and the vascular bundles are collateral. The rhizome of Sirhookera possesses a single-layered epidermis, thick cuticle, thin-walled parenchymatous ground tissue containing starch grains and scattered collateral vascular bundles. A thick-walled sclerenchymatous band separates the cortex from the parenchymatous ground tissue comprising of banded cells in the peduncle. Starch ...