21. Pìnus Banksiàna, Lambert. (Gray or Northern Scrub Pine.) Leaves in twos, short, 1 in. long, oblique, divergent from a close sheath. Cones lateral, conical, oblong, usually curved, 1½ to 2 in. long, the scales thickened at the end and without points. A straggling shrub, sometimes a low tree, found wild in the extreme Northern States.
P. édulis.
P. monophýlla.
22. Pìnus édulis, Engelm. (Piñon or Nut-pine.) Leaves mostly in pairs, rarely in threes, 1 to 1½ in. long, from short sheaths, light-colored, rigid, curved or straightish, spreading; cones sessile, globose or nearly so, 2 in. long; tips of scales thick, conical-truncate, no awns or prickles; seeds large, nut-like, wingless, edible. A low, round-topped tree, branching from near the base, 10 to 25 ft. high; from the Rocky Mountains. A fine small pine; cultivated in the East. It needs some protection at Boston. The figure shows the seed. Pìnus monophýlla, Torr. and Frem., from the mountain regions farther west, has its leaves in ones and twos; when in ones, round and very rigid; when in pairs, flat on the inner side; leaves on the young shoots bluish, glaucous green, or silvery. This is probably only a variety of P. edulis. The seeds of both are so large and nutritious that they are extensively used for food by the Indians.
Genus 94. PÌCEA. (The Spruces.)
Leaves evergreen, scattered (pointing in every direction), needle-shaped, keeled above and below, thus making them somewhat 4-sided. Fertile catkins and cones terminal; cones maturing the first year, pendulous; scales thin, without prickles, persistent, the cone coming off the tree whole.
| * Leaves very short, usually ¼ to ½ in. long, obtuse | 7, 8. | ||
| * Leaves usually ½ in. or more long, acute. (A.) | |||
| A. Cones over 3 in. long; cultivated. (B.) | |||
| B. Leaves dark green; large tree, common | 3. | ||
| B. Leaves bright or pale green | 4, 5, 6. | ||
| A. Cones 2 in. or less long; large native trees | 1, 2. | ||
