Evolutionary significance
Looking through the five species anatomical peculiarities the vascular bundles are much more
similar to that of dicot stem with increasing number of leaves. D. kalkapershadii and D. tomentosa shows
greater affinity towards dicot plant, with palmately compound leaves. Each leaflet bears only one midvein
and broken ring arrangement of vascular bundles. The large vascular bundle shows „Bicolletral‟
appearance. So that D. kalkapershadii and D. tomentosa are the most primitive among the five species,
which are also very rare occurrence in their habitat. D. pentaphylla stands next to first two species, but
shows greater affinity towards D. kalkapershadii in vascular bundle, „Bicolletral‟ nature and compound
leaves. D.hispida shows small similarities to D. bulbifera and greater to D. pentaphylla. The leaflets are
trinerved, vascular bundle are shows small distinction with large and small vascular bundle layers. The
presence of distantly paired nature of vascular bundles present in other two species with compound layers
is absent or not regular in D.hispida.
D. bulbifera shows typical scattered vascular bundle. Both varieties of D. bulbifera are different in
their vasculature and storage cells. The species of D. bulbifera and D. pentaphylla are very common and
showing high degree of mucilaginous content in their stem. Mucilage content is greater in D. bulbifera than
D. pentaphylla.
The similarities of D. hispida with D. dumatorum an African species is very significant. The D.
bulbifera and D. pentaphylla shows wide distribution pattern in world. So the evolutionary significance
also indicates that D. kalkapershadii will disappears in the near future. In The Flora of Presidency of
Madras comment this species as a form of D. pentaphylla. So the need of conservation of this species is
very important.