FAGACEAE 



349 



cup thin and with a thin edge : nut of 



Leaf- blades with rounded broad sinuses ; lobes usually 



dilated near the apex. 

 H Inner scales of the cup inflexed. 

 ff Cup of the acorn turbinate or hemispheric. 



Acorns less than 15 mm. long ; cup hemispheric, less than 15 



mm. broad. 



Acorns over 20 mm. long ; cup turbinate, over 15 mm. broad. 

 ** Leaf-blades pubescent beneath. 



Cup of the acorn turbinate : leaf-blades brown- or rusty-pubescent 



beneath. 



Cup of the acorn saucer-shaped : leaf-blades gray- or white-pubes- 

 cent beneath. 



Large trees : leaves with lanceolate lobes. 

 Leaf-blades rounded at the base ; lobes 3-5. 

 Leaf-blades cuneate or truncate at the base ; lobes 5-13. 

 Shrubs or small trees : leaves with triangular lobes, 

 b. Leaves persistent. 



B. Fruit maturing the first season : stems underground, the branches erect. 

 Leaf -blades, or their teeth or lobes without bristles (except on shoots): nuts often 



glabrous within. 

 Leaves persistent. 



Stems underground, the branches upright. 

 Stems erect. 



Leaf-blades prominently rugose-reticulated : cup of the acorn turbinate. 

 Leaf -blades not rugose-reticulated : cup of the acorn hemispheric (ex- 

 cept in Q.fusiformis). 



Leaf-blades entire (or sometimes spiny-toothed on shoots): nuts fusi- 

 form to ovoid, over 18 mm. long and 9 mm. thick. 

 Acorns less than twice as long as thick ; cup hemispheric ; nut ovoid 



or oblong-ovoid. 



Acorns over twice as long as thick ; cup turbinate ; nut fusiform. 

 Leaf-blades sinuate-toothed : nuts cylindric or oblong-cylindric, less 



than 18 mm. long and 9 mm. thick. 

 Leaves deciduous. 



Leaf-blades entire or sinuate-undulate or merely lobed at the apex. 

 Cup of the acorn saucer-shaped. 

 Leaf-blades pubescent beneath : 



an obovoid type. 

 Leaf-blades glabrous : cup thick and with a thick corky edge : nut of 



an oblong or ovoid type. 

 Cup of the acorn hemispheric. 



Young leaf-blades white beneath ; mature leaves glabrous, prominently 



lobed near the apex. 

 Young leaf-blades tawny beneath ; mature leaves pubescent beneath, 



irregularly lobed or merely angulate. 

 Leaf-blades coarsely toothed or lobed. 

 Leaf-blades toothed or shallowly lobed. 

 Acorns sessile. 



Shrubs or small trees : leaf-blades mostly broadest above the middle. 

 Cup saucer-shaped : margins of the leaf-blades irregular. 



Leaf-blades pubescent beneath : cup thin and with thin edges: 



nut of an obovoid type. 

 Leaf-blades glabrous : cup thick and with a thick corky edge: 



nut of an oblong or ovoid type. 



Cup hemispheric : margins of the leaf-blades regular. 

 Tall trees : leaf-blades mostly broadest below the middle. 

 Acorns peduncled. 



Peduncles shorter than the petioles or about equalling them. 

 Bark close, dark-colored : leaf-blades gray-tomentose beneath. 

 Bark flaky, white: leaf-blades glabrous or white-tomentose 



beneath. 

 Leaf-blades leathery, densely pubescent beneath, with many 



lateral nerves and many relatively small teeth. 

 Leaf-blades membranous, glabrous, with few lateral nerves 



and few large teeth. 



Peduncles much longer than the petioles. 

 Leaf-blades prominently or deeply lobed. 



Mature leaf-blades more or less pubescent beneath : cup fully % as long 



as the nut. 



Upper scales of the cup awned, forming a fringe around the nut. 

 Upper scales of the cup not awned. 



Acorn broader than high ; nut immersed in the cup or nearly so. 

 Acorn longer than broad ; nut about % longer than the cup. * 

 Leaf-blades obovate, gray or yellowish beneath, with 3-5 ample 



dilated lobes. 

 Leaf-blades with rounded upper lobes : cup 11-14 mm. 



broad : nut 12-14 mm. long. 

 Leaf-blades with truncate or emarginate upper lobes : cup 



15-20 mm. broad ; nut 15-20 mm. long. 

 Leaf-blades cuneate, brown or yellowish brown beneath, with 



3-7 low never dilated lobes. 

 Mature leaf-blades glabrous and pale, or glaucous beneath: cup shallow. 



11. Q. Schneckii. 

 13. Q. Catesbaei. 



14. Q. Texana. 



15. 0. coccinea. 



16. Q. velutina. 



17. Q. digitata. 



18. Q. pagodaefolia. 



19. Q. rmna. 



20. Q. myrttfnlia. 



21. Q. pumila. 



22. Q. minima. 



23. Q. geminata. 



24. Q. Virginiana. 



25. Q. fusifoi-mis. 



26. Q. undulata. 



27. Q. Durandi. 



28. Q. Laceyi. 



29. Q. austrina. 



30. Q. Chapmanii. 



31. Q. breviloba. 



28. Q. Laceyi. 



32. Q.prinoides. 



33. Q. acuminata. 



34. Q. Prinus. 



35. Q. Michauxii. 



36. Q. Brayi. 



37. Q. platanoides. 



38. Q. macrocarpa. 



39. Q. lyrata. 



40. Q. Margaretta. 



41. Q. minor. 



42. Q. Boyntonii. 



43. Q. alba. 



1. Quercus Ph611os L. A tree, reaching a maximum height of about 25 m. and a 

 trunk diameter of 1 m., sometimes evergreen, the bark of the trunk nearly smooth. Leaf- 

 blades linear-oblong or narrowly-elliptic, varying to lanceolate or oblanceolate, 4-10 cm. 



