2. Pinus echinata Mill. (short-leaf pine)
Pl. 20g,h; Map 74
Trees to 40 m tall. Trunks with reddish brown to nearly black
bark, the surface breaking into scaly plates. Twigs pale reddish brown or
greenish, glabrous, often glaucous, turning gray to reddish brown with age.
Leaves in fascicles of 2 or 3, 7–12 cm long, with 2 vascular bundles, flexible,
persisting 2–4 years. Fascicle sheaths persistent. Cones 4–6 cm long, brown,
ovoid, symmetrical, not arched, the scales not shiny, with a stout, curved
spine 1–2 mm long near the tip. 2n=24. Pollen shed March–April.
Scattered throughout the Ozark and Ozark Border Divisions,
introduced both within its native range and elsewhere in the state
(southeastern U.S. north to Pennsylvania, west to Texas). Native populations in
mesic to dry upland forests on a variety of acidic substrates, including cherty
slopes; introduced trees mostly in plantations.
Pinus echinata is the only pine native to Missouri and is a characteristic tree of upland forests in the Ozarks. Formerly it was
found fairly extensively in pure stands, these often open and with a diverse
prairielike herbaceous layer. Following the extensive logging of Missouri's forests during the period 1890–1920, it is mostly found as scattered trees in
oak-hickory-pine associations. Gnarled, old individuals several hundred years
old are sometimes found at the edges of glades and bluffs, particularly on
sandstone.