48 HOUGH'S AMERICAN WOODS. 



222. PINUS ATTENUATA, LEMMON. 

 KNOB-CONE PINE, NAKROW-CONE PINE. 



Ger., Fichte mit engen Zapfen; Fr., Pin de cones etroites; Sp. , 

 Pino de conos angostos. 



SPECIFIC CHARACTERS: Leaves in clusters of three each, usually 3-5 in. in 

 length, rather stout, rigid, stomatiferous on all sides, with sharp callous tips, 

 serrate edges, and containing two fibro- vascular bundles and two to five paren- 

 chymatous resin ducts; each fascicle invested at its base with a close sheath, white 

 and loose at margin, about ^ in. in length at first but gradually shorter. Flowers 

 staminate in elongated cylindrical orange-brown spikes, |- in. long and sur- 

 rounded at base by six slightly'fringed involucal bracts; pistillate in oblong spikes 

 about ^ in. in length in verticils of . from 2-6 about the shoot of the year, and 

 raised on short peduncles which are covered with brown fimbricated scarious 

 bracts; the scales of the catkin terminate in long, slender points. Erect at first, 

 these young cones gradually incline outwards and finally at maturity down- 

 wards. Fruit, cones, 3-6 in. long, l-2 in. thick, of a pale brown color at 

 first, elongated-conical, taper-pointed, very oblique and strongly reclined in whorls 

 about the stem; die scales of the inner side being quite flat and armed with a 

 weak incurved prickle, while those of the outer side are furnished with prominent 

 transversely ridged knobs which are tipped with a wide-based incurved prickle. 

 The cones are closed and adhere to the trunk and branches many years, finally 

 becoming gray in color. The narrow tapering bases enables the newly forming 

 wood to gradually encroach upon the cones and some finally become entirely 

 enveloped by the wood The seeds are black, compressed, about 3 lines in length 

 and furnished with lustrous light brown wings -! in. long, widest above the 

 middle. 



(The specific name, attenuata, is the Latin for made thin, and refers to the 

 narrow cones.) 



The Knob-cone Pine is generally a small tree, occasionally attaining 

 the height of 60 or TO ft. (20 m.) and with a trunk 2 ft. (0.60 m.) in 

 diameter, but generally not more than half the above dimensions and 

 often fruiting when not more than four or five ft. in height. It has a 

 rather narrow and irregularly pyramidal head of sparse foliage, the 

 main branches being scattered and irregular and the main stem some- 

 times dividing near the summit into two or three perpendicular 

 branches. The bark of old trunks is of a purple-brown color, 

 weathering to grayish on the surface, and deeply fissured into thick, 

 irregular plates and ridges which exfoliate in small friable scales. 



Its most striking peculiarity is the great quantity of long and 

 narrow cones which persist for many years in whoils about its 

 branches and scattered along its trunk. 



HABITAT. Southwestern Oregon and southward along the western 

 slopes of the Sierra Nevada mountains and the coast ranges to the 

 San Bernardino mountains, only abundant in places and seeming to 

 love the sun-baked slopes where few if any other trees can maintain 

 an existence. It is most abundant and attains its largest size in the 

 northern part of its range where it forms some tracts of open forest. 



