and Australes, are taken from
Engelmann's Revision of the Genus Pinus (Trans. Acad. Sci. St. Louis,
iv. 175-178 [1880]). The remainder, Flexiles, Leiophyllae, Longifoliae,
Insignes and Macrocarpae, are here proposed.

In order to bring the illustrations within the limits of the page the
dimensions of cone and leaf, as shown on the plates, are a little
smaller than life. In plates X and XXV the reproductions of the cones
are reduced to 2/5 life-size.

SECTIONS, SUBSECTIONS, AND GROUPS

Bases of the fascicle-bracts non-decurrent A--HAPLOXYLON

Umbo of the cone-scale terminal a--Cembra

Seeds wingless.
Cones indehiscent I. Cembrae
Cones dehiscent II. Flexiles
Seed with an adnate wing III. Strobi

Umbo of the cone-scale dorsal b--Paracembra

Seeds wingless IV. Cembroides
Seed-wing short, ineffective V. Gerardianae
Seed-wing long, effective VI. Balfourianae

Bases of the fascicle-bracts decurrent B--DIPLOXYLON

Fascicle-sheath or seed of Haploxylon c--Parapinaster

Fascicle-sheath deciduous VII. Leiophyllae
Fascicle-sheath persistent.
Seed-wing of the Strobi VIII. Longifoliae
Seed-wing of the Gerardianae IX. Pineae

Fascicle-sheath persistent, seed-wing
articulate, effective d--Pinaster

Base of wing-blade thin or slightly
thickened.
Cones dehiscent at maturity.
Pits of ray-cells large X. Lariciones
Pits of ray-cells small XI. Australes
Cones serotinous, pits of ray-cells small XII. Insignes
Base of wing-blade very thick XIII. Macrocarpae

HAPLOXYLON

Bases of the bracts subtending leaf-fascicles not decurrent. Staminate
flowers not sufficiently developed in the bud to be apparent.
Spring-shoots uninodal. Fibro-vascular bundle of the leaf single. Cone
symmetrical, of relatively fewer larger scales, its tissues softer.
Bark-formation late, the trunks of young trees smooth. Wood soft and
with little resin, of uniform color and with relatively obscure
definition of the annual rings. Tracheids of the medullary rays wi