82 GENUS PINUS 



two rows of cells. Conelets with long tapering acute scales. Cones from 5 to 8 cm. long, reflexed, 

 ovate-conic, symmetrical, persistent, often serotinous; apophyses lustrous nut-brown, elevated along 

 a transverse keel, the umbo forming a triangular persistent spine. 



A species of limited range, confined to the sandy coast of Alabama and to Florida. It sometimes 

 attains timber-size, but is usually a low spreading tree of no commercial importance and never seen 

 in cultivation. It is recognized by its smooth branches, binate leaves and numerous, often multi- 

 serial, clusters of persistent, often closed, cones. It is associated with P. caribaea and, in the northern 

 part of its range, it grows with the other Southern species. By its close resemblance it may be con- 

 sidered the serotinous form of P. virginiana. 



Plate XXXIII. 



Fig. 288, Three nodal groups of cones of the same year. Fig. 289, Conelet and its enlarged 

 scale. Fig. 290, Leaf-fascicle and magnified leaf-section. Fig. 291, Larger form of the tree. 



54. PINUS RIGIDA 



1768 P. RIGIDA Miller, Gard. Diet. ed. 8. 



1909 P. SEROTINA Long, in Bartonia, ii. 17 (not Michaux). 



Spring-shoots multinodal. Leaves ternate, from 7 to 14 cm. long; resin-ducts medial, or with an 

 occasional internal duct, hypoderm biform. Scales of the conelet abruptly prolonged into a spine. 

 Cones from 3 to 7 cm. long, ovate-conic, symmetrical, persistent, dehiscent at maturity or rarely 

 serotinous; apophyses lustrous tawny yellow, elevated along a transverse keel, the umbo salient and 

 forming the broad base of a slender sharp prickle. 



A tree with bright green foliage in spreading tufts. The northern limit of its range is in southwest- 

 ern New Brunswick, southern Maine, central New Hampshire and Vermont, the Thousand Islands 

 of the St. Lawrence River and central Ohio. It ranges into Pennsylvania and Delaware at low 

 levels and thence over the AUeghanies into northern Georgia. It is associated with P. strobus and 

 P. resinosa and, further south, with P. virginiana. The cones are rarely serotinous, but it is remark- 

 ably like P. serotina in many characters, and is therefore placed in this group. 



Plate XXXIV. 



Fig. 292, Cones. Fig. 293, Leaf-fascicle, magnified section through a fascicle, and magni- 

 fied dermal tissues of the leaf. Fig. 294, Upper part of a tree. 



55. PINUS SEROTINA 



1803 P. SEROTINA Michaux, Fl. Bor. Am. ii. 205. 



Spring-shoots multinodal. Leaves ternate, from 12 to 20 cm. long; resin-ducts medial or medial 

 and internal, hypoderm biform. Conelet long-mucronate. Cones from 5 to 7 cm. long, subglobose or 

 short-ovate, symmetrical, persistent, serotinous; apophyses lustrous tawny yellow, slightly elevated 

 along a transverse keel, the umbo forming the broad base of a slender, rather fragile prickle. 



This species is confined to low wet lands from southeastern Virginia to northern Florida and cen- 

 tral Alabama. It is one of the associated six timber-Pines of the Southern States and the only one 

 of them with serotinous cones. Its wood is of like value with that of P. taeda, the two species being 

 constantly confused by lumbermen. It is never associated with P. rigida, but its resemblance to that 

 Pine is so great that it may be regarded as its serotinous form. Its leaf is longer, its cone usually 

 more orbicular and the prickle weaker. 



Plate XXXIV. 



Fig. 295, Cone. Fig. 296, Conelet and its enlarged scale. Fig. 297, Leaf-fascicle and mag- 

 nified leaf-section. 



