Page 98 - Pharmacognosy-II (06-PG 303)
P. 98
SUBTERRANEAN ORGANS
Introduction
Subterranean organs used in medicine are usually collected from perennial plants where
they serve as storage organs and thus generally are full of reserve food materials.
They are usually rich in carbohydrate such as starch (eg. Rhubab), sugars (Gentian and
squill), inulinc (family compositae) and they are devoid of chlorophyll.
Subterranean organs might be of stem or root origin, while both could be easily
differentiated morphologically as follows:
• Subterranean stems have nodes, internodes, scaly leaves and axillary buds (in the
axis of scaly leaves) which are all absent in subterranean roots.
• Subterranean stems also show adventitious roots.
• Growing point of subterranean stems is protected by a bud (formed of scaly
leaves), while that of subterranean roots is protected by a special tissue called root
cap or calyptra.
92
