JUNIPERACEAE 31 



pressed scales, or sometimes subulate and spreading. Perianth wanting. 

 Staminate aments solitary, variously disposed. Pistillate aments mostly soli- 

 tary, of few carpellary scales. Ovules naked, erect, 1 or several at the base of 

 each carpellary scale. Fruit a cone of often peltate scales, or sometimes fleshy 

 and berry-like or drupaceous. Seeds wingless, or winged, the wing a portion of 

 the testa. Cotyledons 2 or more. 



Plants monoecious ; cones dry : scales merely imbricated. 



Leaves not scale-like, spreading. 1. TAXODIUM. 



Leaves mostly scale-like, typically appressedjand imbricated. 



Cones elongated : scales not peltate : seeds winged at both ends. 2. THUJA. 



Cones nearly globose : scales peltate : seeds slightly winged. 3. CHAMAECYPARIS. 



Plants mostly dioecious : cones berry-like or drupe-like : scales fleshy, coalescent. 

 Leaves subulate and spreading on the mature branches : aments axillary, the 



pistillate with smaller scales at the top. 4. JUNIPERUS. 



Leaves scale-like and appressed on the mature branches : aments terminal, 



the pistillate with larger scales at the top. 5. SABINA. 



1. TAXODIUM L. C. Hich.* 



Deciduous-leaved monoecious trees, with lax branches. Bark thin, smooth, fibrous. 

 Leaves narrow, often almost 2-ranked, normally spreading. Staminate aments in panicled 

 spikes or racemes. Anthers stalked on an oblong column, 2-5-celled, crowded, opening 

 longitudinally. Pistillate aments subglobose, sessile on the branchlets of the preceding 

 year, solitary or in pairs : scales peltate, crowded. Ovules erect, 2 on each scale. Cones 

 globose or obovoid, closed, their scales orbicular or oblong, shield-like, each base narrowed 

 into a stalk. Seeds angled, not winged. Testa shining. Embryo with 6-9 cotyledons. 



Leaves 2-ranked, widely spreading : branchlets horizontal : bark thin, comparatively smooth. 



1. T. distichum. 

 Leaves appressed to the appressed branchlets : bark thick, strongly furrowed. 2. T. imbricarium. 



1. Taxodium distichum (L. ) L. C. Rich. A tree sometimes 49 m. tall and rarely 

 4 m. in diameter above the enlarged base, with soft light, but compact and durable wood. 

 Boots producing hollow conic knees sometimes 2 m. tall : base of the trunk conic, usually 

 hollow, with very prominent narrow longitudinal ridges : bark thin, comparatively smooth : 

 branchlets narrowly horizontal : leaves spreading, 2-ranked ; blades linear, often falcate, 

 1-1.5 cm. long, acute, sessile: Staminate aments 1-2 mm, in diameter, in naked drooping 

 panicled spikes : pistillate aments in the axils of the leaves, with crested scales : cones 

 globular, 2.5 cm. in diameter : seeds 8-10 mm. long. 



In swamps, in or near the coastal plain, usually along the larger rivers and over calcareous rocks, 

 Delaware to Florida and Texas, ascending the Mississippi Valley to Missouri and Indiana. Spring. A 

 Mexican species, T. mucrondtum Tenore, may occur in southern Texas. CYPRESS. BALD CYPRESS. 



2. Taxodium imbricarium (Nutt.) Harper. A tree usually smaller than T. disti- 

 chum, sometimes attaining a height of 25 m. and a diameter of 1 m. above the enlarged 

 base, the wood usually heavier and stronger than that of the preceding species, the knees 

 less abundant and short and rounded. Base of the trunk conoidal, hollow, often 3 or 4 

 times the diameter of the trunk proper, with broad rounded or almost obsolete longitudinal 

 ridges : bark thick, coarse and furrowed : branchlets normally erect : leaves appressed to 

 the branchlets (but on shoots often resembling those of T. distichum), incurved : blades subu- 

 late, 0.5-1 cm. long, sessile : inflorescence and fruit very similar to that of T. distichum. 



In lakes, pine-land ponds, creeks and small rivers in the coastal plain, apparently always over a 

 clay subsoil, Virginia (Dismal Swamp) to Florida and Alabama. Spring. PONI> CYPRESS. 



2. THUJA L. 



Evergreen monoecious shrubs or trees narrowly conic in outline. Branchlets 2-ranked. 

 Leaves scale-like, opposite, 4-ranked, flat or concave, often with a gland on the back, be- 

 coming longer and less densely imbricated on the older parts. Staminate aments terminal, 

 solitary, nearly sessile between the leaves. Anthers in 2 or 3 series, 4-celled, stalked. 

 Pistillate aments solitary, terminal, on short twigs, ovoid or oblong : scales opposite, in 

 several series. Ovules 2 or rarely 3-5, erect at the base of each scale. Cones ovoid or ob- 

 long, drooping, persistent : scales dry, spreading. Seeds flat, broadly winged on both sides. 



1. Thuja occidentalis L. A shrub or small tree reaching a height of 18 m., rarely 

 with a trunk diameter of 1.5 m., producing light and soft but durable wood. Branches 

 zigzag : leaves scale-like, appressed, each bearing a gland on the back, those of the branches 



1 Contributed by Mr. Roland M. Harper. 



