156 . CONIFERALES (RECENT) [CH. 



to the epidermis at each angle. There is a single vascular bundle but no 

 thick- walled hypoderm. Bailey 1 notes the occurrence of wood -parenchyma 

 on the outer face of the summer-wood. The persistent subglobose or more 

 elongated cones, reaching a length of 10 cm. (fig. 705, G), are in most species 

 characterised by the large size of the bract-scales like those of Abies and 

 Pseudotsuga. Bommer calls attention to the superficial resemblance of Larch 

 cones to the fruit of Petropliila diversifolia 2 (Proteaceae). Pseudolarix 

 resembles Larix in habit (fig. 705, A, B); the male strobili are umbellate; 

 the leaves linear lanceolate and up to 7 cm. long. The cones are ovate and 

 bear loosely imbricate, pointed deciduous scales; the bract-scale is shorter 

 than in Larix. Picea. The short and narrow leaves are tetragonal or more 

 or less flat in section : a canal occurs below the vein or there may be two lateral 

 resin-ducts. The persistent bases of the leaves form prominent pegs (fig. 706, 

 D). The cylindrical or oval cones, reaching 16 cm. in length, consist of leathery, 

 concave imbricate scales; the bract-scales are concealed 3 . The stem of a 

 variety of P. excelsa (var. tuberculata}*, characterised by large conical tubercles 

 of cork, bears a close resemblance to that of Xanthoxylum (Rutaceae) 5 . Tsuga. 

 The leaves are flat, decurrent (fig. 706, B), similar to those of Taxus, Abies, and 

 some species of Picea ; but there is a single resin- canal below the vein and the 

 lamina is petiolate and not sessile as in Sequoia sempervirens. In some cases 

 the lamina is finely serrate. The cones closely resemble those of Picea except 

 in their smaller size; the bract-scales are usually concealed, but in T. Pat 

 toniana 6 they are longer and reach a length of 7-5 cm. 



Pseudolsuga. The leaves resemble those of Tsuga, but there are t 

 lateral canals and the lamina is attached by a narrow base to a slightly pro- 

 minent leaf-cushion (fig. 706, C). The wood is like that of Larix but the 

 tracheids often possess spiral bands, and xylem-parenchyma occasionally 

 occurs. Resin-ducts are present in both normal and injured stems. The 

 cones, 5 10 cm. long, resemble those of Tsuga but differ in the 3-pronged 

 conspicuous bract-scale; they are pendulous and the scales are persistent. 

 Keteleeria. Shoots similar in habit to those of Abies; leaves flat, a canal at 

 each angle. Cones similar to those of Pinus Cembra: microstrobili umbellate. 

 Abies. Leaves usually flatter than in Picea and often larger; the apex may 

 be notched though this is not a constant feature 7 . There is no persistent 

 leaf-base (fig. 706, A). Two lateral canals 8 are generally present in the leaf, 

 but in some species the canals are median 9 . Transfusion- tracheids may form a 

 ring round the phloem (A. magnifica). Cones large (in A. nobilis 25 x 10 cm.) 

 and in most species the bract-scales are conspicuous (fig. 705, C, F). The cones 



1 Bailey (09). 2 Bommer, loc. ciL PI. ix. figs. 167, 168. 



3 For figures illustrating the range in form of cones, see Kirchner, Loew, and 

 Schroter (06) pp. 152, 153. 



4 Schroter (97) figs. 24, 26. 



5 Barber (92). 6 Gar A. Chron. June 3, 1893, p. 659. 



7 Kirchner, Loew, and Schroter (06) fig. 26, p. 89. 



8 Ibid. p. 90. 9 Elwes and Henry (06) p. 717. 



apt 



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