ENGELMANN — OAKS OF THE UNITED STATES. 395 



pubescent scales, the acorns mostly ovoid-globose, retu«o, or oval and 

 pointed. I have, with some hesitation, followed DeCandolle and Gray in 

 uniting with this species J^. thictoria, Bart., which has longer and more 

 pointed buds; broader, less lobed and firmer leaves, paler on the under 

 side, smaller and more pointed acorns, at least in the few fruiting speci- 

 mens I have been able to examine, and a deep yellow-colored inner bark. 

 I suspect that specific differences may yet be discovered ; for the present I 

 venture to introduce it as a subspecies. 



=^>. Georgiana, M. A. Curtis, confined, as far as known, to that isolated 

 granite rock, the Stone Mountain, east of Atlanta in Georgia, which is also 

 the only locality for Gymnoloma (formerly Rudbeckia) Porteri, Gray, and 

 for Isoldes mela'nosfiora.* Leaves glabrous from the first, generally lance- 

 oval, oval or sometimes obovate, mostly coarsely sinuate-toothed, with 2-4 

 teeth or lobes, rarely pinnatifid or sometimes entire or undulate; crowded 

 acorns small, subglobose ; shallow, flat cups, truncate or rarely rounded at 

 base, with triangular, obtuse, nearly glabrous, appressed scales. Perhaps 

 too near ^>. palustris, from which the fruit is scarcely distinguishable, 

 though the locality, the growth and the foliage differ. 



^. laurifolia, Michx., appears after all to be distinct from ^. aquatica ; 

 whether entire or lobed, the leaves of the latter mostly have a cuneate out- 

 line widest in the upper third or at least above the middle; the calyx lobes 

 are larger and very conspicuous, and the filaments enclosed and only the 

 anthers exsert. Q. laurifolia has lanceolate oblong leaves, widest about 

 the middle whether entire or lobed ; the calyx lobes are much small- 

 er; filaments exsert; this in flowering specimens of both species from 

 Bluffton, the only ones which I could compare. A specimen from the 

 gulf coast of Mississippi has oval entire coriaceous leaves 4 inches long 

 and \\ inches wide, while those of the South Carolina plants are narrower, 

 and rather approach to Phellos, but never to aquatica. They usually per- 

 sist until the budding time, but not beyond it. 



^>. cinerea, Michx. In specimens from South Carolina I find, together 

 with the ordinary stellate pubescence, an abundance of yellow articulated 



* Isortes melanospora. n. sp. amphibia, parvula, gregaria, plerumque monoica; trunco 

 placentiformi bilobo; foliis paucis (5-10) distichis stomatosis sine fasciculis fibrosis peri- 

 phericis ; velo sporangium suborbiculare totum tegente ; macrosporiis (0.35-045 mm. 

 diam.) minutissime sub lente verruculosis obscuris (humidis nigricantibus) , microsporiis 

 (0.02S-0.031 mm. longis) papillosis obscuris. 



In shallow depressions a couple of inches deep and a few feet in diameter, on the naked 

 granite surface near the top of the mountain, where occasional rains and dews furnish tem- 

 porary and precarious moisture, but where for weeks and even months the glaring sun, 

 flashing on the naked rock, parches and bakes them : discovered by Wm. M. Canby in 

 May, 1S69; revisited by Prof. Gray in April, 1S75, and by Mr. Canby and myself in Septem- 

 ber, 1S76, when nothing was perceptible but ihe dead, matted rooVfibres "attached to the 

 small shrivelled conns. — Corm 3-4. lines in diameter, flat, only y z -\ lin^ thick; leaves 2-2^ 

 inches long, in all the specimens examined distichous, which I have not seen in any other 

 species: sporangia >2-', l line in diameter, usually emarginate above, almost black from then- 

 dark contents, but without any brown cells ; often rtmaining for a time attached by then- 

 base when their leaf has withered away. The plant, which I have cultivated for several 

 years, seems to vegetate as soon as moisture is furnished, but lies dormant part of the year: 

 spores mature in May and June. — This species, I. flaccida from Florida, and I. Nut'tallii 

 from Oregon, are the only American Iso'elet in whjch the spore case is entirely enclosed in 

 and covered by the velum; and it is the only one of ours with dark spores, all the others 

 having white ones. 



