CLASS XXIV. ORDER I. 409 



eighty feet. Its branches are opposite, and covered with bark 

 of a very light color. Leaves pinnate, consisting of about 

 seven oval, acuminated leafets, whitish underneath, entire or 

 slightly toothed. The flowers grow in loose panicles from the 

 axils of the last year's leaves. Their stalks have opposite 

 branches with bracles at base. The barren flowers consist sim- 

 ply of two large, oblong, reddish anthers, proceeding from a 

 minute dentated tubercle which seems to be a calyx. The fer- 

 tile ones have a small calyx, an ovate germ, and a long style 

 ending in two stigmas. They are succeeded by winged capsules, 

 which are cylindrical at base, but dilated at their end into a 

 long, flat appendage, somewhat lanceolate in form, but blunt or 

 emarginate at the end. The wood of the common Ash is ex- 

 ceedingly durable, firm, and elastic, with a tolerable degree of 

 lightness. It is the principal material used in the manufacture 

 of carriage frames, of light agricultural implements, of oars, 

 blocks, boxes, &c. — May. 



Class XXIV. CRYPTOGAMIA. Fructification 

 anomalous or concealed. 



Order I. FILICES. Ferm. 



420. Equisetum. Floral receptacles peltate, many 

 angled, collected into a spike; indusinm corniculate ; 

 stamina four ; style none ; seed one. 



421. Lycopodium. Capsules reniform, one celled, 

 two valved, many seeded; seeds very minute, resem- 

 bling powder. 



422. BoTRYCHiUM. Capsules subglobose adnate to 

 the rachis of the compound raceme, separate, naked, 

 one celled ; valves two, connected behind, opening 

 transversely. 



423. Lygodium. Spikes unilateral ; capsules in two 

 series, opening on the inner side from the base to the 



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