When thus ascending, it
makes no use of its tendrils or petioles; but when it twined round a
rather thick stick, and its petioles were brought into contact with
it, these curved round the stick, showing that they have some degree
of irritability. The petioles also exhibit a slight degree of
spontaneous movement; for in one case they certainly described
minute, irregular, vertical ellipses. The tendrils apparently curve
themselves spontaneously to the same side with the petioles; but from
various causes, it was difficult to observe the movement of either
the tendrils or petioles, in this and the two following species. The
tendrils are so closely similar in all respects to those of B.
unguis, that one description will suffice.
Bignonia unguis.--The young shoots revolve, but less regularly and
less quickly than those of the last species. The stem twines
imperfectly round a vertical stick, sometimes reversing its
direction, in the same manner as described in so many leaf-climbers;
and this plant though possessing tendrils, climbs to a certain extent
like a leaf-climber. Each leaf consists of a petiole bearing a pair
of leaflets, and terminates in a tendril, which is formed by the
modification of three leaflets, and closely resembles that above
figured (fig.
Pages:
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122