60 



BRITISH EOCENE ELORA. 



Tribe VI.— ABIETINE^. 



The genera Pinus, Cedrus, Picea, Tsuga^ Pseudotsuc/a, Abies, and Larix are recognised 

 by Bentham and Hooker in the Genera Plantarum, 1880. The tribe is most extensive, 

 comprising some 150 species, inckiding the Pines, Firs, Cedars, and Larches, and is 

 almost exclusively confined to northern, and north temperate regions. There are no 

 tropical species, and only one Pine in the Sunda Isles, including Sumatra, Java, and 

 Borneo. The genera are all needle-leaved and cone-bearing, and with few exceptions 

 produce winged samaroid seeds. 



The Abietinese did not make their appearance until after the other tribes of Coniferse 

 had long existed, and no remains of them are known of date older than the Jurassic. 

 "With the Wealden and Cretaceous periods they became plentiful, and already in the 

 Neocomian and Gault the ancestors of several existing genera were completely 

 differentiated. There are not wanting signs that in the later Tertiaries at least, they had 

 acquired almost as great an extension as at present. The vast preponderance of fossil 

 wood is, it is well known, coniferous, this being from its resinous nature capable of 

 resisting decay, when immersed or buried, for a much longer time than ordinary 

 Exogenous wood ; but it is remarkable how very large a proportion of the Coniferous wood 

 from the Tertiaries belongs to the Abietineae, though the woods of other tribes surpass it 

 in this property. Of upwards of a thousand specimens from the Brown-coal, examined 

 by Goeppert, only three were not coniferous ; and of all the woods from the underlying 

 Amber-beds, only one could be referred to another tribe of Conifers. 



It is difficult to estimate the area occupied at the present day by the Abietinese, but 

 in northern regions they are held to outnumber the broad-leaved trees by ten to one. 

 In Europe Pinus syhestris and P. cemhra stretch from the most westerly Alps, across the 

 Black Sea, to the Caucasus and Altai, and, uniting with Abies sibirica and Larix sibirica, 

 form the colossal forests of Siberia, estimated at 1,200,000 square miles. In America 

 the Pine-barrens stretch 300 to 500 miles uninterruptedly. In British North America, 

 forests occupying 240,000 square miles are formed of Abies nigra, A. canadensis, and 

 Larix microcarpa. Their colossal bulk and great economic importance have been already 

 alluded to, but it was not mentioned that species of this tribe furnished the whole 

 of the Amber of North Germany, and of these the value of the Samland deposits alone 

 is estimated at £250,000,000. 



The Abietinese are represented in British Eocenes exclusively by the genus Pinus. 

 It is remarkable that hardly any traces of them have been met with in any of the Floras 

 in which leaves are preserved, their remains consisting only of cones, having, in the 

 British rocks, been found almost exclusively in marine or estuarine deposits. The 

 localities from which they have been collected are numerous, but except those from below 



