Gymnosperms : Coniferae Pinoideae Abietineae. VIII. 



ABIETINEAE: a series of generic types (9), more or less isolated, but 

 approaching the type of Pinus in many features of special organization, as in needle- 

 foliage, timber-construction, mechanism of floral-shoots, and definite ' cones ', in which 

 the cone-scales are spirally arranged, each bearing 2 inverted ovules only, and 

 constituting the predominant, externally visible feature of the fruiting structure. 



The group includes Pinus (70), as the largest genus, and distinctly the most 

 highly specialized type of the series ; Pinus alone having spur-shoots restricted to 2-5 

 needles, and woody cones with conspicuous cone-scale facet (apophysis and umbo). 

 Picea (20), Abies (26), and Larix (14) are the more generalized types; the last 

 distinguished by its assumption of the deciduous habit; these 3 genera are widely 

 distributed over the whole of the N. Temp, forest region of Europe, Asia, and N. Amer. 



Other types are more isolated, and represent vestigial forms of intermediate 

 specialization ; e. g. Cedrus, localized in mountains of the Old World, approaching 

 Larix in its spur-shoot-system. Pseudolarix, a monotype of Eastern China, is 

 deciduous. Keteleeria is also a Chinese monotype. The remaining genera are 

 restricted to N. America (with extensions to the Asiatic side of the Pacific), Tsuga (7) 

 a more generalized type, and Pseudotsuga, a more elaborate form, combining 

 characters of Picea and Abies. 



These associated genera cannot be arranged in any linear scheme, but each may 

 be regarded as presenting a partial retention of a set of factors common to the older 

 race, as variants on a general theme in which some types have passed beyond 

 the others, though stationary or even retrograde in other respects. 



I. CEDRUS (3), forest-trees of N. Subtropical forest-belt, Old World: as 

 geographical races, C. Deodara (Himalya), C. Libani (Syria), C. atlantica (Atlas Mts.) ; 

 of organization older and more generalized than Pinus, with special phases of 

 xeromorphic habit ; the type is : 



Cedrus Libani (Lebanon, Asia Minor, and Cyprus), attaining 2,000-3,000 years: 

 90-120 ft.: diam. max. 34 ft. Evergreen; main leader erect, laterals horizontal, 

 pyramidal at first, table-topped later. 



Annual shoot; 6-8 inches (3 in. on weaker laterals) : primary leaves spirally 

 arranged as slender needles, 15-30 mm. Terminal bud with conoidal apex at base 

 of crater, for protection of primordia (cf. longit. sect.). Relics of leaf-scars and winter 

 bud-scales persist for 10 yrs. on bark. No false whorls of leader laterals. In axils of 

 a few leaves of current year (without rule), but more towards the end of the shoot, 

 spurs are produced in the first season, as spiral clusters of a few (8-13) short needles 

 (10-12 mm.). Primary needles fall in 2nd and 3rd year. Subsequent foliage from 

 spurs only; in the second season these produce 20-30 needles (20 mm.), with 

 terminal crateriform bud. Spur-foliage may persist for 2-3, or even 4-6 years. 

 Growth of spurs is continuous, with leaf-production over 15 or more seasons, 

 averaging 21 needles each year. 



Dorsiventral shoot-systems. All spurs erect to the upper side of horizontally 

 spreading laterals ; so exaggerated on older axes that they appear borne on upper 

 surface only. Dense growths of short spurs give the door-mat effect of the foliage- 

 system. Spurs may branch occasionally, not more than one lateral as a short spur in 

 one season ; and any spur with illumination may grow out as a leader ; a large 

 number of intermediate stages assist in the aggregated mat of foliage. Old spurs show 

 a characteristic 'jointed' system of segments (2-3 mm.), in which scars of the needles 

 (2 cycles) alternate with the spiral bud-scales of the old terminal buds. This may 

 continue for 15 years or more : spurs have no annual rings in the xylem. 



Staminate flower large and conspicuous, borne terminating spur-shoots on 

 growth several years (5-7) old: formed in August and functional in September, 

 October; erected, 30 mm. in bud, 3 in. when expanded ; including 300-400 stamens, 

 in spiral series : stamens 4 mm. with connective crest bent up at right angles : Pollen 

 2-winged, 50 /x diam., 80 /x across wings. Shed in November. 



Ovulate flowers with similar position, few, inconspicuous, small green-purple 

 cones, -| inch long, erected ; ovules 2 on scale, and inverted. Cone-scale functional 

 in pollen-collection, Oct.; full size in succeeding June at fertilization-stage, as 



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