This group represents the first stage in the evolution of the Hard Pines. All the species, like the Soft Pines, are uninodal and the cones are dehiscent at maturity, but the trend toward the serotinous species is shown in the occasional appearance of the oblique cone as a varietal form of a few species, and in the persistent cone of the last two species of this group.
All the species of this group are of the Old World except P. resinosa and P. tropicalis. These two are the only American Pines combining large pits with dentate tracheids, and are the only American Hard Pines with external resin-ducts of the leaf.
| Cones deciduous at maturity. | |
| Cones ovate or ovate-conic. | |
| Conelet with tuberculate or entire scales. | |
| Resin-ducts external and medial | 25. resinosa |
| Resin-ducts septal and external | 26. tropicalis |
| Conelet with mucronate scales. | |
| Resin-ducts mostly external. | |
| Conelet pedunculate, erect. | |
| Cone nut-brown | 27. Massoniana |
| Cone dull tawny yellow | 28. densiflora |
| Conelet pedunculate, reflexed | 29. sylvestris |
| Conelet subsessile, erect | 30. montana |
| Resin-ducts mostly medial. | |
| Bark-formation late | 31. luchuensis |
| Bark-formation early. | |
| Cone nut-brown | 32. Thunbergii |
| Cone lustrous tawny yellow | 33. nigra |
| Cones narrow cylindrical | 34. Merkusii |
| Cones tenaciously persistent. | |
| Leaves stout, relatively short | 35. sinensis |
| Leaves slender, relatively long | 36. insularis |
25. PINUS RESINOSA
- 1789 P. resinosa Aiton, Hort. Kew. iii. 367.
- 1810 P. rubra Michaux f. Hist. Arbr. Am. i. 45, t. 1.
Spring-shoots uninodal. Leaves binate, from 12 to 17 cm. long; resin-ducts external or external and medial; hypoderm uniform and inconspicuous. Scales of the conelet mutic. Cones from 4 to 6 cm. long, subsessile, symmetrical, deciduous the third year, leaving a few basal scales on the tree; apophyses sublustrous, nut-brown, somewhat thickened along a transverse keel.
From Nova Scotia and Lake St. John this species ranges westward to the Winnipeg River and southward into Minnesota, Michigan, northern New York and eastern Massachusetts, with rare occurrence on the mountains of Pennsylvania. Under cultivation it is a beautiful tree, adapted to cold-temperate climates. It was considered by Loiseleur (1812) and by Spach (1842) to be a variety of P. nigra (laricio). The two species vary in the color of the cone, the anatomy of the leaves, the buds, and in the armature of the conelet. A fallen cone of this species is moreover usually imperfect from the loss of a few basal scales.
Fig. 170, Cone and enlarged conelet. Fig. 171, Leaf-fascicle and magnified leaf-section.