XLHl] SCIADOPITIHTEAB, SEQUOnNEAE, CALLITRINEAE 151 



more appressed and smaller, decussate or in close spirals {A. cupressoides) or, 

 in A. laxifolia^, more like the foliage of Sequoia gigantea. The apex of each 

 cone-scale has a sharp point at the distal end. TetracUnis (fig. 703, B). This 

 genus, which occurs in Algeria and Morocco, and is usually placed next to 

 Callitris and WiMringtonia, has recently been transferred by Saxton^, as the 

 result of his work on the life- history of T. arliculata, to the Cupressineae : he 

 believes that the CaUitrineae were derived from the Northern Cupressineae 

 through some type resembling TetracUnis. The flattened foHage-shoots 

 reseinble Salicomia and bear 4-ranked small leaves; the cones consist of 

 4 nearly equal decussate scales, each scale having 2 seeds with unequal wings. 



SCIADOPITINEAE. Sciadopitys. The single species is characterised by 

 the long and rigid 'double needle' reaching a length of 12 cm. with a broad 

 furrow on the upper surface and a deeper groove on the lower face. Mr 

 Boodle^ has recently described an example of concrescence in needles of Pinus 

 Laricio Poir. var. nigricans Pari, which points to the probabiUty that a morpho- 

 logical similarity exists between the double needle of Sciadopitys and abnormal, 

 fused, leaves of Pinus. Reference is made by Boodle to other possible views 

 that have been advanced with regard, to the morphological nature of Sciadopitys 

 needles. The oblong woody cones, 7x4 cm.* are fairly easy to identify by 

 the rounded and reflexed upper margins of the scales (fig. 684, S) ; there are 

 5 — 15 seeds, with a narrow wing, on each cone-scale. 



SEQUOIINEAE. Sequoia. Attention has already been called to some 

 of the anatomical features. The oval pits on the field (2 — 6) have an upper 

 and a lower border though the pore is not infrequently obhquely vertical. 

 Anatomically the wood of S. sempervirens is considered by Gothan^ to agree 

 more closely with that of Taxodium than with S. gigantea. The leaves of 

 S. gigantea {=Wellingtonia) axe 3-angled and decurrent, -5 mm. long; those 

 on the fertile shoots are broader, shorter and imbricate. S. sempervirens 

 bears 2-ranked linear, sessile, but not decurrent leaves with an abruptly 

 spinous apex. There is a resin-canal below the midrib and transfusion- 

 tracheids form conspicuous lateral groups. The cones of the two species are 

 of the same type, but those of S. gigantea are larger and occasionally reach a 

 length of 9—10 cm. (fig. 702). 



CALLITBINEAE. The foliage-shoots, similar to those of some Jumpers, 

 are characterised by short decurrent scale-like leaves in alternate ternary 

 or decussate whorls; the ovate or globular cones are composed of a few 

 valvate scales. Actinostrobus" (fig. 703, A). The very small leaves in ternary 

 whorls have a free apex and the slender shoots closely simulate those of some 

 species of Veronica and Thamnea depressa (Bruniaceae). The 6 cone-scales 

 are oblong, acute, and the base of the cone is invested by 6 rows of crowded 

 scales which gradually pass into the foUage-leaves : each scale has 2 — 3 winged 



. 1 Oard. Chron. Jan. 31, 1891, p. 147. ^ Saxton (13=); (13'). 



3 Boodle (15). / Siebold (70) PI. CTi 



5Gothan(06); (09). See also Jeffrey (03) ; Gordon (12). . 

 6 Saxton (13). 



