A comparative study was carried out to ascertain the effects of particulate
matter on the gross morphological and leaf epidermal features of some tropical plants. Two
populations of
Xanthosoma mafaffa
Schott,
Chromolaena odorata
(L.)
King and Robinson,
and
Ageratum conyzoides
(L.) were collected; one from an unpolluted area and the other from
a polluted environment (generated from an asphalt production industry). Plants from the
polluted area show marked reduction in leaf size and area, and reduced chlorophyll content
in leaves. There were chlorotic and necrotic leaf spots on the species from polluted area and
an average leaf area of 94.81 cm
2, 15.81 cm
2, and 17.29 cm
2 for
X. mafaffa,
C. odorata and
A. conyzoides respectively while the non-polluted species had no leaf spots and an average
leaf area of 181.95cm
2, 36.75 cm
2, and 32.11cm
2 for
X. mafaffa,
C. odorata and
A. conyzoides
respectively. Length and width of stomatal pore of leaves from polluted area had increased
number of stomata, but the length and width of stomata were reduced by -12.89% and -
08.42%, -19.54% and -28.60% and -27.50% and -37.86% in the length and width of
X. mafaffa,
C. odorata and
A. conyzoides respectively, as compared to the leaf samples from
unpolluted area. Also, epidermal cells decreased compared to the leaves from unpolluted
area, while the density of epidermal cells per unit area increased. These suggest that these
plants are under air pollution stress and the results are adaptive and compensated mechanism
to the adverse effects of the particulate matter.
