396 ' ABOUT THE OAKS OF THE UNITED STATES. 
annual acorns, by lanceolate thick leaves with revolute margins, and a white tomentose lower surface. The 5-lobed 
calyx is scarcely hairy and bears 4 stamens; no bracts seen, even before the flowers open. 
13. Q. pumina, Walt. Fl. Carol. p. 234 ; Michx, Sylv. tab. 17 (where the fruit is erroneously represented as 
biennial, otherwise the figure is good). This interesting shrub, though first described nearly a century ago, has only, 
through the efforts of Dr. J. H. ‘MMichasx, become properly known in the !ast few years. Living in the immediate 
vicinity of its habitat, the pine barrens of the low country of South Carolina, this acute observer has aided me in t 
ost liberal manner in studying this as well as other difficult oaks of that region 
Q. pumila is called the running-oak because, by the aid of its wide-spreading stolons, it covers large patches, 
sometimes acres, with its thickets. It is often, especially where kept down by the frequent fires, only 1-2 feet high, 
and has been seen loaded with flowers when only of 6 inches; in other localities it grows 8-10 feet high, with stems 1 
inch in diameter. The leaves, revolute in vernation, are usually about 2 inches long, lanceolate, entire, and often 
undulate, only occasionally dentate-lobed, but in vigorous shoots sometimes broad ovate and deeply and acutely 
lobed; another form has obovate obtuse leaves. They are slightly pubescent when young, but soon become quite 
glabrous, persist through the winter and occasionally beyond the flowering period. In the male flowers I find pretty 
arly 4 stamens, and in the female 3 long recurved styles. The globose fruit in its shallow cup is nearly sessile 
in the axils of the same year’s leaves. — Q. pumila, Walt., Michx. Sylv., Nutt. Gen., Elliott Flor. @. Phellos, var. 
pumila, Mich. Querc. & Flor. Q. cinerea, var. pussitA, Chace A. DeCand. Prod. 
Var. sericea has similar narrow, or larger, ovate-lanceolate leaves, always silky-white underneath; the larger 
leaves on fertile branches grow over 4 inches long by 1} inches in width, and on sterile shoots even larger. — Q. sert- 
cea, Willd., Pursh. Q. Phellos, var. sericea, Ait. 
Over a year has passed since the foregoing part of this paper was published; a the [885 (1)] 
concluding seven pages, only a small edition, for private distribution, was then prin 
Contsnacd: study of the genus, aided by numerous kind communications of sein ek. as well as 
of specimens, have enabled me to make the following corrections and additions. 
Page 374, 1. 22. bast shrubby forms of Q. stellata occur on the southeastern sea-coast, and of Q. macrocarpa on 
the northwestern p. 
L. 2 from ‘ahi soot to read: the only oak wood, —The wood of Q. Prinus, however, makes an exception, 
being more porous than most other white-oak wo 
A careful study of the numerous American oak woods displayed by the Agricultural Department and by differ- 
ent States, at the Centennial Exhibition in Philadelphia, has revealed further interesting facts. The black-oaks grow, 
on an average, nearly twice as fast as the white-oaks, and if Q. nigra and the evergreen black-oaks be left aside, the 
disproportion will be found still greater. In the average of 20 different white-oaks, from all parts of the country, I 
find the growth nearly equal through the first 40 years; in 14 specimens of black-oaks the growth is more rapid in 
the first 30 years than between the 30th and 40th. The following little table will exhibit this more distinctly. 
Average Width of the Annual Rings. 
in 20 white-oaks : in 14 black-oaks : 
In the first 20 yea’ Pek ee ee eS Oe SN RO. eS SS eee 
Ts on 20th to the soth year Oe ee om Cr eg eee ie eae Oa an geri Pee FS jetta 
30th Oth ear pele Masta SG UNG ve het he aa aL yearns | “y cag Sas ee ee oe 
The heartwood of the white-oaks is always readily distinguishable from the sapwood by its darker color, varying 
between dark gray and light brown, but in the black-oaks the heartwood is scarcely darker than the sap, and in some 
species or some individuals cannot be distinguished at all. Only in Q. nigra and the curious Q. Emoryi is it often 
irregularly mottled with black. 
In the limited number of specimens which I could examine, the sap turned into heartwood, 
in 19 white-oaks, in 8 black-oaks, 
after ea Si ae We ee ; ot yaa CTT years, 
having stad a ‘hickhies of. Pe . « . Sipe se es... ST lines. 
Only in these 8 black-oaks a line of demarcation was visible. 
* The pages referred to (385-391, 14-20 of the private edition), which we omit from this reprint, were replaced by simi- 
larly numbered > the Transactions of the Academy (pp. 1-7 of the reprint of this second part), as directed in a slip 
distributed with it. — 
