18 FLORA OF PHILADELPHIA. 



5a. Isoetes Engelmanni YsAMda Engelm, M,, p. 29. Ponds and ditches. 

 Autumn. 

 Lancaster— Smithville (P.). 

 56. Isoetes Engelmanni gracilis Engelm., M. p. ,29. Ponds and ditches. 

 Autumn. 

 Bucks— Sellersville (Pr.). Delaware— Tinicum (P.). 



Subkingdom SPERMAPHYTA. 



Class 1. GYMNOSPERMAE. 

 • u ,,-.,.. Order, L; PINTLES., ; ;• 



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



berry-like. Pam. 1. Pinaceae. 



Pistillate flowers solitary, without carpellary scales; fruit drupaceous or 



baccate. Earn. 2., Taxaceae. 



Family 1. PINACEAE Lindl. Pine Family. Conifers. 



Scales of the cone numerous; leaf -buds sealy., 



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



, 1. Sinus. , , 

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

 sheaths. ' f 2. Tsuga. 



Scales of the cone few (3-12) ;, leaf -buds naked. , , 1/ 



Cone globose, its scales peltate. 3. Chamaecyparis. 



Pruit fleshy, berry-like, a modified cone. 4. Juniperus. 



1. PINUS L. 



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



1. P. Stroius. 

 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. Virgi/iiiana. 



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 r (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 Steobus L." White P'ine. M. p; 31. In woods, frequently' in 



cultivation. Early summer. 



Bucks— Rock Hill (Fr.), Buckingham (Ws.). M ontgomery— Shannon^ 



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



Haverford (Le.), Concord (W. Tr.).- Chester^ (P.). Lancaster— (P.). 



Lehigh — Lehigh Mountain (Kr.). 



Camden— Berlin (C). Gloucester— Woodbury (C), Swedesboro (Li.). 

 Monmouth— Pinebrook (C). Middlesex-^ >Woodbridge (C). 



