Pinus attenuata
Pinus cembroides
knobcone pine
Mexican pinyon, pino piñonero, piñón
purple-brown to dark brown, shallowly and narrowly fissured, with irregular, flat, loose-scaly plates, on upper sections of trunk nearly smooth.
red-brown to dark brown, shallowly and irregularly furrowed, ridges broad, scaly.
ascending;
twigs slender, red-brown.
spreading-ascending;
twigs red-brown, sometimes finely papillate, aging gray to gray-brown.
ovoid to ovoid-cylindric, dark red-brown, aging darker, ca. 1.5cm, resinous;
scale margins fringed, apex attenuate.
ovoid to short cylindric, pale red-brown, 0.5–1.2cm, slightly resinous.
3 per fascicle, spreading or ascending, persisting 4–5 years, (8–)9–15(–20)cm × (1–)1.3–1.8mm, straight or slightly curved, twisted, yellow-green, all surfaces with fine stomatal lines, margins serrulate, apex abruptly conic-subulate;
sheath (1–)1.5–2cm, base persistent.
(2–)3(–4) per fascicle, spreading to upcurved, persisting 3–4 years, 2–6cm × 0.6–0.9(–1)mm, connivent, 2–3-sided, blue- to gray-green, abaxial surface not conspicuously whitened with stomatal bands or if stomatal bands present, these less conspicuous than on adaxial surfaces, often with 2 subepidermal resin bands evident, adaxial surfaces conspicuously whitened with stomatal lines, margins entire to finely serrulate, apex narrowly conic or subulate;
sheath 0.5–0.7cm, scales soon recurved, forming rosette, shed early.
ellipsoid-cylindric, 10–15mm, orange-brown.
ellipsoid, to 10mm, yellow.
cones maturing in 2 years, serotinous, long-persistent, remaining closed for 20 years or more, or opening on burning, in whorls, hard and heavy, very asymmetric, lanceoloid before opening, ovoid-cylindric when open, 8–15cm, yellow- or pale red-brown, stalks to 1cm;
apophyses toward outside base increasingly elongate, mammillate or raised-angled-conic, downcurved near base, scarcely raised on branchlet side, rhombic;
umbo central, low-pyramidal, sharp, upcurved.
cones maturing in 2 years, shedding seeds and falling soon thereafter, spreading, symmetric, ovoid before opening, broadly depressed-ovoid to nearly globose when open, 1–3.5cm, pale yellow- to pale red-brown, resinous, nearly sessile or short-stalked;
apophyses thickened, slightly domed, angulate, transversely keeled;
umbo subcentral, slightly raised to depressed, truncate or umbilicate.
=24.
=24.
Pinus attenuata
Pinus cembroides
Pinus attenuata, mostly a chaparral species, bears cones at an early age. Its seed crops are heavy, and a hot fire permits the seeds to be released. It forms hybrids with P. muricata and P. radiata.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Pinus cembroides is the common pinyon of Mexican commerce. Populations of the Edwards Plateau, Texas, are disjunct about 150km east and north of the main area of distribution of the species, and they have been described as a distinct variety, P. cembroides var. remota Little, on the basis of thin seed shell and a higher frequency of 2-leaved fascicles in contrast to the thicker seed shell and prevalently 3-leaved fascicles in Mexican pinyon populations to the west and south. The strong overlap in nearly all character states between the populations of the Edwards Plateau and other populations makes var. remota difficult to maintain.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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