CLIMBERS, PARASITES, SAPROPHYTES. 201 



the flanks of the stem. Note (1) the leaf -base, swollen and partly 

 ensheathing the stem ; (2) the cylindrical stalk, varying in length ; 

 (3) the blade, dark green, often pale along the veins or in patches, 

 glossy, leathery, evergreen. The young leaves are all alike, but by the 

 bending of the leaf -base or pulvinus, the amount of lengthening of the 

 stalk, and amount of surface-growth of the blade, the leaves are 

 brought into a horizontal position with the blades fitting together to 

 form a "leaf -mosaic." The buds are covered with down, consisting of 

 minute star-shaped hairs, which can be seen scattered over the stem 

 and leaves after the bud has unfolded ; by noting the arrangement of 

 the hairs it is easy to trace the amount of growth of stem, leaf-stalk, 

 and leaf -blade. 



233. Hook Climbers. Some plants climb, often in a 

 rather straggling or rambling fashion (e.g. Brambles, Eoses), 

 by means of hooked prickles. 



An interesting example is the Common G-oosegrass (Galium 

 aparine), which belongs to the same family (Rubiaceae) as 

 the Bedstraws, and is very common in hedgerows. 



The seedlings of Goosegrass (seen in autumn and winter) have large 

 green oval cotyledons, and at first the shoot grows erect. The stem is 

 4-sided, and the leaves are arranged in circles or whorls, the number 

 varying from 4 in a whorl in the seedling to 8 or 9 in the older parts of 

 the plant. Note the small prickles on the stem and leaves. Are the 

 prickles straight or curved ? In what direction do they curve ? Are 

 they scattered evenly all round the stem ? Sketch a part of the shoot 

 showing the arrangement of the prickles. 



Do you think all the parts in a whorl are really leaves ? Do they all 

 bear buds and branches in their axils ? If not, how many do so ? Note 

 that the true leaves are in opposite pairs, the pairs of successive 

 whorls being crossed, so that the true leaves are in 4 rows on the stem. 

 The other appendages in each whorl are leaf -like stipules. There are 

 always two leaves (distinguished by having buds or branches in their 

 axils), and the number of other parts in the whorl depends on the 

 extent to which the stipules branch on the one hand, or ' ' fuse " (grow 

 together) on the other. Note how the shoots of Goosegrass insinuate 

 themselves between the branches and leaves of the hedge-plants. 



One often sees the seedlings growing in crowded patches, some right 

 below the hedge, others out in the open ; which seedlings perish 

 soonest, and why ? The Goosegrass is one of the most interesting and 

 instructive plants found in hedgerows, and careful observations, at 

 frequent intervals, of patches of its seedlings offer a fine example of the 

 fierce struggle for existence, which is keenest in places like hedgerows 

 (why ?), and of the advantages (and disadvantages) accruing to a plant 

 which is adapted to a special mode of life, such as the climbing habit. 

 Note the great extent to which the Goosegrass grows in a, single season ; 

 it is an annual plant. 



