496 BOTANY PAKT n 



Most important Genera and Species. Ayathis'(Dammara) is distributed in 

 the Malayan Archipelago and extends to New Zealand ; A. australis and A. 

 Dammara yield Kauri Copal but no Dammar Resin ; Araucaria brasiliana and A. 

 imbricata are stately, S. American, forest trees ; A. excelsa, A. Cookii, and other 

 species with very limited distribution are extensively cultivated as ornamental 

 trees. The genus Sequoia includes the most gigantic trees known ; specimens of 

 S. gignntca from the California!! Sierra Nevada attain a height of 100 m. and' a 

 diameter of 12 m. 



European Forest Trees. Picea excelsa, the Fir (Fig. 463), is a fine tree of 

 pyramidal shape ; it has no short shoots, and the long shoots bear on all sides 

 pointed, quadrangular, needle-shaped leaves, which on horizontal or pendulous 

 branches stand more or less erect. Male flowers as a rule on shoots of the previous 

 year ; on flowering they become twisted into an erect position. The two pollen- 

 sacs open by a longitudinal slit. Female flowers terminal on the shoots of the 

 previous year usually near the summit of the tree. They stand erect at the tiim- 

 of flowering. The ripe cones are pendulous and, after setting the seeds free from 

 between the scales, fall in pieces. The development of the seeds is completed in 

 one year. The male and female flowers occur on the same individual. Picen 

 orientalis from Asia Minor, and Picea alba from N. America are frequently 

 cultivated. 



The Silver Fir (Abies pectinata, Fig. 462) is a native of the mountains of the 

 middle and south of Europe. It bears only long shoots. The flat, needle-like 

 leaves, marked below by two white lines and emarginate at the tip, are borne on all 

 sides of the axis, but are twisted- into a horizontal position on the branches 

 illuminated from above. The male flowers stand in the leaf-axils on the under 

 side or on the flanks of the shoot, and grow downwards so that the pollen-sacs are 

 directed upwards. The wall of the sporangium opens by an obliquely longitudinal 

 split, which gapes widely and allows the winged microspores to escape. The 

 female flowers arise from the upper side of a branch and are directed vertically 

 upwards. The bract-scales are longer than the broad, ovuliferous scales. The 

 fertilised cones retain the upright position, and when ripe the scales separate from 

 the axis and so set the seeds free from the plant. The development of the seeds 

 takes a year. Abies Nordmanniana from the Caucasus, A. pinsapo from Spain, 

 A. concolor, A. balsamea, and A. nobilis from N. America are in cultivation. 



Larix europaea, tlie Larch, is one of the few deciduous Conifers and replace* its 

 foliage annually. There is a differentiation into long and short shoots. The 

 former bear the narrow linear leaves on all sides and continue the branching of the 

 pyramidal tree the lower branches of which often droop downwards. The short 

 shoots arise in the axils of the leaves of the long shoots of the preceding year, 

 and bear a rosette of 30-40 leaves which are somewhat shorter but resemble those 

 of the long shoots. The flowers occur in a position corresponding to that of the 

 short shoots. The male flowers are bent downwards when fully developed, and 

 the opening of the upwardly directed pollen-sacs occurs as in Abies. The erect 

 female cones produce seed in the same year. 



The most advanced differentiation of the vegetative organs is found in the 

 genus Pinus ; P. silvestris, the Scotch Fir, will serve as an example (Fig. 464). 

 Young seedlings in the first or second year have long shoots bearing needle-shaped 

 leaves. On older plants this type of foliage is lost ; the needles are replaced by 

 colourless, membranous scale leaves in the axils of which stand the short shoots. 

 These have 2 in other species 3 or 5 needle-shaped foliage leaves. The latter 

 are about 5 cm. in length, their flat surfaces are turned to face one another and the 



