花叶开唇兰营养体的结构

THE STRUCTURE OF NUTRITIVE BODY IN ANOECTOCHILUS ROXBURGHII

Anoectochilus roxburghii (Wall.) Lindle. is a perennial terrestrial orchid, which has rhizome. There are endodermises in its stem and root. The Casparian strip thickening occurs on the endodermis. The number of protoxylem groups in root is five to nine. In stem, 12-18 vascular bundles are arranged in 2-3 circles. Palisade tissue and spongy tissue can be distinguished in the mesophyll. In the former, the chloroplasts are bigger and dark green; in the latter, the chloroplasts are smaller and pale green. The stomata are scattered on the lower epidermis. The arrangement of subsidiary cells is irregular. The cells of upper epidermis are often papillae. In the parenchyma cells of root, stem and leaf, the raphides exist in clusters accompanied by grains of polysaccharides. In some of the parenchyma cells in cortex of root, there are clusters of symbiotic fungal hyphae.