jivaka :

Morphology:

M. acuminata is a small, medium-sized terrestrial orchid, up to 30 cm in length, with pseudobulbous stem covered at base by old leafy scales. Leaves 3-4, ovate- lanceolate, membranous and measuring 10-15  5-6.5 cm showing acute apex and undulate margins. Flower pale-green tinged purple, shortly stalked, 1-1.2 cm across, present on many flowered, 8-10 cm long spikes; bracts linear, minute. Sepals oblong; lateral broad and short with recurved margins. Petals are linear, longer than sepals. Lip shield like, broadly ovate, somewhat convex, tip notched, auricles at base straight or overlapping. Leaves have sheathing leaf base and new plants grow near the base of the decaying mother plant. Flowers, in terminal racemes, are small, pale yellowish-green in color, but with a purple tinge.

Fresh pseudo bulb conical in shape, fleshy, green, smooth, shining, 1 to 9 cm long and 1 to 3 cm broad, slightly mucilagenous, covered with shining, transluscent light green, membraneous, 3 or 4 sheathing leaves arranged alternately and having parallel venation; stem rudimentary; roots arising at the union of stem and bulb.

Dried pseudo bulbs conical, transluscent, reddish-brown in colour, measuring 2 to 5 cm long and 0.25 to 1 cm wide, covered with sheathing leaves, which are light brown, membraneous with parallel venation; surface rough, punctated, fracture hard; cut surface dark brown, coarsely granulated with irregular margins and white spots; pleasant smell; astringent, slightly mucilagenous in taste

Histology:

T.S. of pseudo bulb oval to circular in outline; section passing through scaly leaves which exfoliate, showing a single layered, thick walled, sclerified epidermis having acicular crystals of calcium oxalate, followed by mesophyll adjacent to the upper epidermis composed of 2 to 4 layers of elongated cells with lignified reticulate thickening the lignification was confirmed with phloroglucinol and Conc. HCl, devoid of chlorolplast; vascular bundles prominent, phloem well developed with large sieve plates, surrounded by sclerenchymatous bundle sheath; section passing through bulb shows a single layer of cuticle and a layer of thick walled sclerified epidermal cells; below this lie 1 or 2 layers of large sclerified cells and these extend unevenly into ground parenchymatous tissue; ground parenchyma irregular, with large air spaces with passage cells in the form of small protuberances at some places; vascular bundles scattered throughout the ground tissue surrounded by thick walled sclerenchymatous cells, which occasionally extend into intercellular spaces.

Dr Mohamed Rifas

A dual country licensed Ayurveda Physician, currently working in Dubai as Head of Ayurveda and Yoga department. He also works as visiting doctor for Dr Hassan Ayurveda Brain and Spine Specialty Hospital. He is specialized in joint issues, brain and spine related issues and gastrointestinal issues with respect to anxiety.
Doctor profile: Click here