Prev | Current Page 108 | Next

Darwin, Charles, 1809-1882

"The Movements and Habits of Climbing Plants"

--TENDRIL-BEARERS.

Nature of tendrils--BIGNONIACEAE, various species of, and their
different modes of climbing--Tendrils which avoid the light and creep
into crevices--Development of adhesive discs--Excellent adaptations
for seizing different kinds of supports.--POLEMONIACEAE--Cobaea
scandens much branched and hooked tendrils, their manner of action--
LEGUMINOSAE--COMPOSITAE--SMILACEAE--Smilax aspera, its inefficient
tendrils--FUMARIACEAE--Corydalis claviculata, its state intermediate
between that of a leaf-climber and a tendril-bearer.
By tendrils I mean filamentary organs, sensitive to contact and used
exclusively for climbing. By this definition, spines, hooks and
rootlets, all of which are used for climbing, are excluded. True
tendrils are formed by the modification of leaves with their
petioles, of flower-peduncles, branches, {24} and perhaps stipules.
Mohl, who includes under the name of tendrils various organs having a
similar external appearance, classes them according to their
homological nature, as being modified leaves, flower-peduncles, &c.
This would be an excellent scheme; but I observe that botanists are
by no means unanimous on the homological nature of certain tendrils.


Pages:
96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120