EXGELMANN OAKS OF THE UNITED STATES. 3S1 



wood, styles long and spreading or recurved, abortive ovules al- 

 ways near the tip of the perfect seed. The leaves and their lobes 

 are bristle-pointed, at least in youth ; lobes and teeth acute ; teeth 

 sometimes spinous. Their stamens are usually less numerous, the 

 scales of their cup membranaceous, the inner surface of their nut 

 always tomentose ; the fruit generally matures in the second year : 



We may then arrange our oaks in the following order : 

 Quercus, Lin. 



I- LepidobalailUS, Endl. : Amenta mascula pendula; pollinis cellulas 



0.03-0.04 mm. latse; flores feminei a masculis distincti: stigmata dilatata. 



A. Leucobalanus : Ovulaabortiva infera vel raro lateralia ; stamina 



plerumque 6-8; stigmata sessilia vel subsessilia; mix intus glabra s. 



rarissime pubescens. 



* Maturatio annua; nux intus glabra; ovula abortiva infera. 



f Folia decidua. 

 Q. lyrata, 1 macrocarpa," 1 alba, lobata, stellata, Garryana, bico- 

 lor, Micfiaitxii,' 6 Prinus, 4 frinoides, Douglasii, undulata. 5 

 f ■( Folia sempervirentia. 

 «^>. dumosa, 6 Emory i.' reticulata,* virens. 9 



** Maturatio biennis; nux intus pubescens; ovula abortiva infera vel latera- 

 lia ; folia sempervirentia. 



Jg. chrysolepis. 10 

 b. Melanobalanus : Ovula abortiva supera; stamina plerumque 

 4-6; stvli elongati demum recurvi; nux intus sericeo-tomentosa. 



* Maturatio annua; folia persistentia s. subpersistentia. 

 Q. agrifolia, 1 l hyfoleuca, 1 2 pumila. J 3 



* * Maturatio biennis. 



I Folia decidua. 

 Q. fialustris, rubra, Sonometisis, cocci?iea, li ilicifolia, Georgia- 

 na, Catcsbcei, falcata, nigra, cif/erea, 15 aquatica, laiirifolia, 1 * 

 heterofihylla, x ~ imbricaria, Phellos. 



t | Folia sempervirentia. 

 4£. IVislizeni, 1 * myrtifolia. 19 

 II. Androgyne, A. DeC. : Amenta mascula erecta, basi fiores femineos 

 gerentia; pollinis cellulre fere 0.017 latse ; stigmata linearia. 

 J9. de?isifiora. 



NOTES. 



1. Quercus lyrata, Walt., extends as far north as Taxodium does, to tTie 

 banks of the lower Ohio in Illinois. 



t. Q. macrocarpa, Michx.,is extremely variable in the-size of its acorns, 

 and especially in the depth and the margin of its cup. which sometimes 



