18 FLORA OF PHILADELPHIA. 



5a. IsoETES Engelmanni valida Engelin. M. p. 29. Ponds and ditches. 

 Autumn. 

 Lancaster— Smithville (P.). 

 5b. IsoETES Engelmanni gracilis Engelm, M. p. 29. Ponds and ditches. 

 Autumn. 

 jBucA's— Sellersville (Fr.). De?au-are— Tinicum (P.). 



Subkingclom SPERMAPHYTA. 



Class 1. GYMNOSPERMAE. 

 Order 1. FINALES. 



Pistillate flowers several, with carpellary scales; fruit a cone, either dry or 

 berry-like. Fam. 1. Pittuceae. 



Pistillate flowers solitary, without carpellary scales; fruit drupaceous or 

 baccate. Fam. 2. laxaceae. 



I^amilyl. PINACEAE Lindl. Pine Family. Conifers. 



Scales of the cone numerous; leaf -buds scaly. 



Cone-scales woody; leaves needle-shaped, 2-5 in a sheath. 



1. Pinus. 

 Cone-scales thin; leaves linear-filiform, solitary or clustered without 

 sheaths. 2. Tsuga. 



Scales of the cone few (3-12) ; leaf-buds naked. 



Cone globose, its scales peltate. 3. Chamaecy parts. 



Fruit fleshy, berry-like, a modified cone. 4. Jwniperus. 



1. PINUS L. 



Leaves 5 in a sheath ; cone-scales little thickened at the tip. 



1. P. Strobus. 

 Leaves 2-3 in a sheath ; cone-scales much thickened at the tip. 

 Leaves some or all of them in 2 's. 



Cones conic, 3-7 cm. long, their scales tipped with prickles. 



Leaves stout, 3-6 cm. long. 2. P. Firginiana. 



Leaves slender, 7-13 cm. long. 3. P. echinata. 



Cones 8-12 cm. long, their scales tipped with very stout, short 

 spines. 4. P. pungens. 



Leaves in 3 's (very rarely in 2 's or 4's). 



Leaves 1.5-2.5 dm. long; old sheaths 1-2.5 cm. long; cones oblong- 

 conic. 5. P. Taeda. 

 Leaves 7-13 cm. long; old sheaths 0.6-1.2 cm. long; cones ovoid, 

 base flat. 6. P. rigida. 



1. PiNUS Strobus L. White Pine. M. p. 31. In woods, frequently in 



cultivation. Early summer. 



Buclcs — Rock Hill (Fr.), Buckingham (Ws.). Montgomery — Shannon- 



ville (Cr.), Edge Hill (Re.), Schuylkill at Lafayette (Ws.). Delaware— 



Haverford (Le.), Concord (W. Tr.). C}iester—{V.). Lancaster — (P.). 



Lehigh — Lehigh Mountain (Kr.). 



Camden — Berlin (C). Gloucester— y^oo&hvirj (C), Swedesboro (Li.). 

 Monmo^dh — Pinebrook (C). Middlesex — Woodbridge (C). 



