342 INTRODUCTION TO PLANT GEOGRAPHY [CHAP. 



the same genera (apart from Hickory) but different species are 

 usually involved in the deciduous forests, examples among the Ashes 

 being Fraxinus mandshurica and among the Birches Betiila ermanii, 

 while the Beech Fagus crenata characterizes fine * Buna ' forests. 



3. The Beech forests which, especially in Europe, where Fagus 

 syhmtica is the species involved, form an almost uniform closed 

 canopy, intercepting the sunlight so effectively that few^ shrubs and 

 herbs can grow below. The trunks are tall and slender, particularly 

 when the trees grow closely together, and few competitors of the 

 dominant Beeches are able to enter their preserve. \ thick brown 

 mat of fallen leaves and leaf-mould covers the ground. It is chiefly 

 in early spring before the Beech leaves expand that small perennial 

 herbs such as Bluebell {Endymion {Scilla) non-scriptus) and Wood 

 Anemone {Anemone nemorosa) tend to flourish as a prevernal aspect, 

 often growing gregariously to form attractive carpets. Otherwise 

 herbs are characteristically few, sometimes being largely limited 

 to nongreen saprophytes, while the lower shrubs may consist of 

 no more than scraggy Brambles (Riibus spp.) in the more open areas. 

 Occasional Ash, Wild Cherrv, White-beam {Sorbiis aria s.l.), or 

 other trees may reach the height of the canopy, or Hollies or Yews 

 form a scraggy subordinate layer. The commonest tall shrubs are 

 Elder {Sambucus nigra) and Field Maple, with Spindle-tree [Euony- 

 mus europaeus), Dogwood {Cornus sangiiinea), and Wayfaring Tree 

 {Vibiirmim lantana) occurring chiefly in openings. 



4. Southern Beech (especially Nothofagus antarctica) forests, 

 usually with associated evergreens such as Drimys zvinteri, of southern 

 South America. The trees are closely crowded, shrubs again being 

 relatively few. Ferns and Bryophytes, on the other hand, are 

 numerous and often extremely luxuriant, the latter sometimes 

 forming an almost continuous carpet over the ground and fallen 

 logs, etc., and extending well up the standing trunks. 



5. The damper aspect of deciduous woodland developed especially 

 on marshy ground subject to inundation, and dominated by various 

 Alders {Alnus spp.). Willows {Salix spp.), Poplars, Birches, and the 

 like, with often a tangle of hygrophytic shrubs. Climbers and 

 epiphytes may be plentiful, and on the moist ground often flourish 

 coarse herbs and tussocks of tall Grasses, Sedges, and Ferns such as 

 the Royal Fern {Osmunda regalis agg.). These marshy thickets are 

 plentiful in temperate regions on both sides of the North Atlantic, 

 and appear to represent late stages in the hydrosere. 



In addition, the Sweet Chestnut forests of various parts of southern 



