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 ...本研究对隶属于兰科（Orchidaceae）树兰亚科（Epidendroideae）的锡尔胡克兰属（Sirhookera）的营养器官、花序梗解剖特征及菌根形态进行了比较分析，旨在明确该属物种鉴定的解剖标记，并揭示其生态适应性。披针叶锡尔胡克兰（Sirhookera lanceolata）的叶片为下生气孔型（hypostomatic），具四细胞型气孔器（tetracytic stomata），其副卫细胞细胞壁光滑；阔叶锡尔胡克兰（Sirhookera latifolia）的副卫细胞细胞壁呈波状。该属植物叶片的近轴面与远轴面均被厚角质层覆盖。叶片的皮下组织为二型结构，分布于叶片两侧；叶肉绿色组织（chlorenchyma）均一，维管束为外韧型（collateral vascular bundles）。锡尔胡克兰属的根状茎具单层表皮、厚角质层，由薄壁组织构成的基本组织富含淀粉粒（starch grains），且散生有外韧维管束。在花序梗中，厚壁的厚壁组织带将皮层与由带状细胞构成的薄壁基本组织分隔开来。淀粉……