WOODS AND COPSES 



243 



rule. The pedunculate Oak has wet-soil con- 

 ditions, the sessile being adapted to dry-soil 

 conditions. 



The woodlands on calcareous soils (Carboni- 

 ferous Limestone, Chalk, Oolite) afford in the 

 case of Ash woods varied habitats or types of 

 association, the plants being often gregarious, 

 as in the case of Dog's Mercury and Arch- 

 angel. They rise to some altitude. On marls 

 the Ash-Oak woods are variable in the types 

 of association. In the case of Beech woods 

 the habitat is upland very largely, and dry, 

 there being a scanty scrub and ground flora. 



The Habit of Woodland Plants. The wet 

 or dry character of the woodland determines 

 largely the nature of the habit. Thus in 

 Alder- Willow woodland associations the plants, 

 such as Rushes, Grasses, and Sedges, with the 

 grass habit are largely tufted or ca^spitose. 

 Even the rosette types are frequently tufted, 

 as in the case of Marsh Marigold and Bitter- 

 cress. The procumbent or trailing habit is 

 also characteristic. These habits are transi- 

 tional to the submerged and floating habits of 

 purely aquatic plants, which are intimately 

 associated with fen formations. 



In the normal dry woodlands the tree habit 

 is the dominant one. The scrub is analogous 

 to that of the tree habit, but is always influenced 

 by the tree zone. The stems and branches are 

 less strong, and thick, the leaves are small, 

 and often several times pinnate. Spines are 

 more numerous, and the flowers are more 

 suited in most cases to pollination by insects. 



The ground flora is variable in habit. There 

 is the climbing habit of the Ivy or the Honey- 

 suckle, &c. , adapted to reliance upon the sup- 

 port of trees or scrub. The bulbous or tuber- 

 ous habit is especially typical, e.g. Bluebell, 

 Orchids. A large number of plants are pros- 

 trate or procumbent, or provided with creeping 

 underground stems, as Strawberry, Wood 

 Anemone. 



Flowering Seasons in the Woods. The shade 

 conditions in a woodland have a marked effect 

 upon the periods of flowering. There are thus, 

 apart from the general seasons of flowering in 

 May, June, and July, when the sunlight is fuller 

 and stronger, early-flowering plants and late- 

 flowering plants. Those plants that flower 

 early, seize the opportunity of doing so before 

 the leaves of the trees appear, or at least before 

 the foliage is fully developed. The growth 

 season of bulbous plants is short, and they 

 flower early in consequence. 



The earlier plants to bloom in the woods are 

 the Winter Aconite, Snowdrop, Lesser Celan- 

 dine, Spurge Laurel, &c. 



The trees themselves largely flower before 

 the leaves, owing to their adaptation for wind 

 VOL. III. 



pollination, as the pollen would be less likely 

 to be dispersed when the leaves are fully ex- 

 panded. The Willows depend partly on the 

 wind, partly on insects, and so flower early. 



The scrub is largely influenced by the same 

 factors also. The Hazel relies on wind pol- 

 lination, and is the earliest to flower. The 

 Blackthorn also flowers before the leaves ap- 

 pear, since it is more conspicuous then than 

 later. The Grasses, in spite of the fact that 

 they are chiefly wind-pollinated, flower, as a 

 rule, rather late in the woods. 



The late-flowering groups are chiefly the 

 Hawkweeds, rosette plants whose scapes are 

 long. The Brambles, owing to the great out- 

 put of stems and branches, also flower late. 

 The latest plant to flower of all plants is a 

 woodland plant, the Ivy. 



Height of Woodland Plants. A particular 

 feature of the woodlands is the height of the 

 dominant type, the trees. It is largely owing 

 to their height, which is regulated to a con- 

 siderable extent by the wind and soil, that they 

 are the dominant type of plant, next to Grasses, 

 in the world flora itself. 



This character enables them to outstrip other 

 plants in the struggle for sunlight and air. 

 They are thereby enabled to counteract the 

 influence of all other classes of plants, which 

 growing below do not affect them in these 

 respects. These facts require special emphasis. 



The lower strata of plants are directly in- 

 fluenced as regards height (and other factors 

 equally) by the dominance of the tree zone. 

 This is seen in its greatest extreme in a Beech 

 wood, where the ground flora is often nil. 



The scrub, e.g. Blackthorn, Elder, &c., 

 suffers less than the ground flora, and this is 

 seen in clearings, where the scrub may rival 

 the younger trees in height, &c. Like the 

 tree zone, the scrub normally has a definite 

 upper limit. The undershrubs, that are in 

 turn dominated by the scrub or large shrubs 

 and smaller trees, also approximate in height 

 to a certain standard. 



The ground flora is of course influenced 

 most by being covered by two strata above. 

 Consequently, as a rule, it also approximates 

 to a certain general height, e.g. Grasses, and 

 others with the grass habit. Orchids and 

 bulbous plants come next. Then there are 

 the trailers, such as the Barren Strawberry; 

 and lastly the mosses and hepatics. 



Life Duration of Woodland Plants. As a rule, 

 shade plants are perennial, whilst the annuals 

 and the biennials are to be found amongst the 

 sun plants. A feature of the woods, dominated 

 by the tree type as they are, is the deciduous 

 character of the vegetation, at least in the cold 

 temperate zone. This is an adaptation to 



46 a- 



