PLANTS OF NORTHERN GUJARAT 
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3. Other Spermopliyta— • 
Monochoria hastcefolia , Polygonum serrulatum, Glossostigma 
spathulatum , Mriocaulon trilohum , Ammannia baceifera , 
A. salicif 'olia i A , tenuis , A. auriculata , A. multifiora , 
Aeschynomene indica , Hygrophila polysperma , Ludwigia 
parvifora Asteracantha longifolia, Hydrolea zeylanica i 
Melookia corchorifolia f Sesbania acute at a , Corohorus spp. 
Caesulia axillaris i Blumea eriantha i Sphenoclea zeylanica % 
Tamarix dioica , Alternanthera triandra, 
II. Dried Mud Formation . 
This includes only one association, differing but slightly in different 
localities. It is excluded by the Reed-Swamp associations from places 
where the more upright and vigorous plants just described can gain a 
footing. The two factors which lend to exclude the Heed- Swamp, and 
clear the way for the present association appear to be (1) proximity of 
Acacia arabica^ and (£) repeated trampling of the ground by cattle 
drinking and buffaloes wallowing. The prejudicial effect exercised on 
other vegetation by Acacia arabica is well known, and the extensive 
tracts covered by that tree in the regions north and west of Ahmedabad 
are very poor in herbaceous plants. This fact is also recognized by 
the cultivators who prefer to remove Acacia arabica from the borders of 
their fields. As regards the second factor mentioned above it is to be 
noted that the country near Ahmedabad is both thickly populated and 
overstocked with cattle, especially buffaloes, which are maintained for the 
milk supply of the city. The small tanks in this region are, therefore, 
usually occupied by this association. The members are all prostrate, and 
are provided with a long tap root. They are all capable of enduring a 
period of submergence, which varies from one to nine months, and they 
seem to be almost indifferent as to its length. In fact there is little 
doubt that in years of very light rainfall these plants re-appear on 
ground which for several years has not been free of water. We are 
not certain whether they are annuals or perennials but it seems at 
least probable that a majority must be perennial. There are good 
reasons for assuming that these are plants which have been driven into 
their present habitats through competition, and have acquired their 
prostrat3 rosette habit after reaching those habitats. This was borne 
out by observations made in 1915-16 in tank beds not usually cultivated, 
but in which cultivation of wheat was allowed that season on account 
of the quasi-famine conditions, when it was noticed that under the 
stimuli of decreased light intensity, competition from surrounding crops, 
and continual gentle irrigation, Trigonella occulta , Gnaphalium indicum 
