=4.= =Salix frágilis= Linnæus. Willow. Crack Willow. Plate 13. Tree very similar to _Salix alba_; twigs very brittle at the base (hence the name), green to reddish; petioles 7-15 mm. (1/4-5/8 inch) long, glandular just below the base of the leaf; leaves lanceolate, acuminate, 7-15 cm. (3-6 inches) long, 2-3.5 cm. (4/5-1-1/2 inches) wide, coarsely serrate with 5-6 teeth to each cm. (2/5 inch) of margin, dark green and shining above, paler to glaucous beneath, rarely green, glabrous on both sides; catkins appearing with the leaves in late April and during May, 4-8 cm. (1-1/2-3 inches) long; capsules slenderly conical, 4-5 mm. (1/5 inch) long, on pedicels 0.5-1 mm. (1/16 inch) long. [Illustration: Plate 12. SALIX ALBA Linnæus. White Willow. (× 1/2.)] [Illustration: Plate 13. SALIX FRAGILIS Linnæus. Crack Willow. (× 1/2.)] =Distribution.=--A native of Europe. It has been frequently planted and often escapes. Specimens have been seen from the following Indiana counties: Benton (Deam); Clark (Deam); Laporte (Deam); Switzerland (Deam); Union (Deam); Wells (Deam). =Economic Uses.=--This species and the white willow are introduced from Europe and extensively grown for the production of charcoal to use in powder making. =5.= =Salix díscolor= Muhlenberg. Pussy Willow. Swamp Willow. Glaucous Willow. Plate 14. Shrub or small tree, 2-4 or occasionally 7-5 m. (7-15 or 25 feet) high; bark thin, usually smooth, reddish brown; twigs stoutish, reddish-purple to dark brown, often pubescent (see the variety); buds large, 5-10 mm. (1/5-2/5 inch) long, colored as the twigs; stipules large, mostly roundish, entire or toothed; leaves short-lanceolate to elliptic or elliptic-oblanceolate, acute or short-acuminate at the apex, rounded or acute at the base, 5-10 cm. (2-4 inches) long, 2-3.5 cm. (4/5-1-1/2 inches) wide, nearly entire to coarsely wavy-toothed on the margins, dark shining green above, densely glaucous and occasionally somewhat pubescent beneath, especially on midrib and primaries; flowers appear in late March or in April before the leaves; catkins sessile, on old wood, stout, dense, the staminate very beautiful (pussies), without leaf-bracts at base, 2-5 cm. (1-2 inches) long, the pistillate becoming 3-8 cm. (1-1/2-3 inches) long in fruit; scales elliptic-oblanceolate, densely clothed with long shining hairs; capsules conic-rostrate, 7-10 or 12 mm. (1/4-1/2 inch) long, densely gray-woolly; pedicels 1.5-3 mm. (1/16-1/8 inch) long.