360 REVISION OF THE GENUS PINUS. 
line broad, strongly serrulate ; bracts lightly fringed, subpersistent ; sheaths 9 lines long, at length reduced to 1 line: 
male flowers oval, 6 to 8 lines long, in spikes an inch long ; involucre half as long as the flowers, of 6 or 8 bracts, the 
outer as long as the inner : cones sessile, spreading or more or less recurved, in clusters of 4 to 7, often remaining closed 
and long-persistent, ovate and very oblique, chestnut-brown, 2 to 3} (usually 3) inches long and 1} to 2 inches thick ; 
prickles short and stout or (in the southern form) making long straightish or incurved spurs on the outside; seeds 3 
lines — grooved and rough, black ; wing 6 to 8 lines long, widest above the middle: cotyledons 4 or 5. — Torr. 
lic. t., 54. P. Edgariana, Hartw. 1. ¢. 
ge near the coast, where it is sae to the sea winds and fogs, to an altitude of 2,000 feet, from Mendocino, 
where it grows tallest (in peat-bogs), to Tomales Point (in the most sterile soil), Monterey and San Luis Obispo. In 
many respects similar to the last, but readily distinguished by the leaves being in pairs and by the short thick cones. 
‘he specimens collected at Tomales Point (Brewer, Bolander) have subterminal cones, but seem to differ in no other 
respect. The cones are said to persist over 30 years. 
IX. REVISION OF THE GENUS PINUS,* AND DESCRIPTION OF PINUS ELLIOTTII. 
FroM THE TRANSACTIONS OF THE St. Louris ACADEMY OF ScIENCE, Vol. IV. 1880. 
No difficulty exists in the circumscription of the genus Pinus; floral unite with vegeta- [161] 
tive characters to establish it so firmly and so plainly, that nobody fails to recognize the species 
_ belonging to it. But when we come to analyze and to group the 60 or 70 species of pines which 
are known to us, we find that they appear so similar, that all attempts to arrange them satisfactorily 
have failed. The most obvious distinctive character was found in the number of leaves in each 
bundle, and thus the sections of 2-leaved, 3-leaved and 5-leaved pines were the only ones known to 
the older botanists. _Spach (Syst. veg. 1834) separated Cembra on account of its “ wingless ” seeds ; 
Link (Linnea, 1841) relied on the number of leaves only, adding two sections, one;with 2 or 3, the 
other with 3 or 4 leaves in a sheath; Endlicher (Synopsis, 1847) was the first to point out the form 
of the cone-scales as an important character, and his first two sections, Cembra and Strobus, were by 
the form of this scale distinguished from the other Pines; he retained the character of the “ large 
wingless” seeds, to separate by it Cembra from Strobus, and Pinea from the other two-leaved pines 
which constituted his section Pinaster. Later writers did not add anything to our knowledge of the 
systematic relations of pines: Carriére (Coniféres, 1855) copied Endlicher, and Gordon (Pinetum, 
1858) went back to the mere number of leaves to characterize the sections. Ten years later Parlatore 
(DeCand. Prod. xvi. 2, 1868) followed Endlicher in adopting the differences in the form of cone-scales 
as the most valuable character, and advanced a step further by discarding the proportionate size of 
the seeds as of sectional value. He divided his subgenus Pinus in two sections, Pinea with pyrami- 
date and Cembra with dimidiate apophyses. The subsections of his Pinea were again based on the 
number of leaves, in twos, in threes, or in fives in each bundle ; those with single leaves, with 2 or 3, 
and those with 3, 4 or 5 leaves had to find their place as best they could 
Not satisfied with such superficial knowledge of this interesting and important genus of [162] 
trees, I have for a number of years devoted my leisure hours to the careful study of the 
different species accessible to me. In the following pages I give the principal results of my 
investigations. 
Sizz. Almost all the pine species grow up to be trees; the only shrubby one known to me is 
Pinus montana, heretofore known as P. Pumilio; a few make small, insignificant trees, such as 
P. tuberculata ; the nut pines, or cembroid pines, never grow large, but several others attain the 
greatest dimensions ; P, Lambertiana grows to the height of 300 feet, with 20 feet in diameter, and 
* The account of this genus in Gray’s Manual, 5 ed. 1868, pp. a Sil 0, is based on notes contributed by Dr. Engelmann. 
The article “‘ Pinus” (in the Linnzan a in Johnson’s new Illustrated Universal Cyclopedia, New York, 1877, Vol. Ill. 
pp- 1256, 1257, is also from his pen. — 
