64 The New York State College of Forestry 



FRUIT KEY TO THE SPECIES — (Continued) pag^ 



23. Fruit a double samara or key 24 



23. Fruit a single samara 29 



24. Fruit in racemose clusters 25 



24. Fruit in corj^mbose or umbellate clusters 27 



25. Wings lf-2 inches long Acer Negundo 301 



25. Wings 1 inch or less in length 26 



26. Wings about ^ of an inch long, slightly divergent Acer spicatum 2')1 



26. Wings about f of an inch long, widely divergent . . Acer pennsylvanicum 289 



27. Fruit maturing in spring or early summer 28 



27. Fruit maturing in the autumn Acer saccharum 293 



Acer saccharum, var. nigrum 295 



28. Wings ^-1 inch long, slightly divergent Acer rubrum 299 



28. Wings 1-2 inches long, widelj' divergent Acer saccharinum 297 



29. Samara 2-celled and 2-seeded Ptelea trifoliata 275 



29. Samara 1-celled and 1-seeded 30 



30. Wing terminal 31 



30. Wing surrounding the seed 33 



31. Wing rounded or acute at the apex Fraxinus pennsylvanica 329 



Fraxinus pennsylvanica, var. lanceolata 331 



31. Wing emarginate or rarely pointed at the apex 32 



32. Samara oblong to linear-spatulate; apex pointed or emarginate 



Fraxinus americana 327 

 32. Samara lanceolate-oblong to linear-oblong; apex conspicuously 



emarginate Fraxinus nigra 333 



33. Fruit in paniculate clusters; samaras oblong-linear, 1^-2 inches long 



Ailanthus glandulosa 277 

 33. Fruit in racemose or umbellate clusters; samaras oval-orbicular to obovate- 



oblong less than 1 inch long 34 



34. ^Margin of samara not ciliate; seminal cavity pubescent on the face. . . . 



Ulmusfulva 201 



34. Margin of samara ciliate 35 



35. Surface of samara pubescent Ulmus racemosa 205 



35. Surface of samara glabrous LUmus americana 203 



36. Fruit a nut subtended by a cup-hke or foliaceous involucre 37 



36. Fruit a leathery drupe or drupaceous nut 39 



37. Involucre cup-like; fruit an acorn 38 



37. Involucre fohaceous, trilobed Carpinus caroliniana 159 



38. Acorns maturing at the end of the first season; shell of nut glabrous on 



the inner surface White Oaks 360 



38. Acorns maturing at the end of the second season; shell of nut silky- 



tomentose on the inner surface Red or Black Oaks 360 



39. Fruit less than | of an inch long 40 



39. Fruit over 1 inch long 42 



40. Fruit in cymose clusters, adnate to a ligulate bract 41 



40. Fruit solitary Celtis occidentalis 207 



41. Fruit ovoid Tilia americana 307 



41. Fruit globose or subglobose Tilia heterophylla, var. Michauxii 311 



Tiha Michauxii 309 



42. Xut ovoid or elhpsoid, 2-celled at base Juglans cinerea 141 



42. Nut globose or rarely oblong, 4-celled at base Juglans nigra 143 



43. Fruit a pome 44 



43. Fruit a drupe or berry 50 



44. Fruits in racemose clusters; pome 10-celled Amelanchier canadensis 241 



Amelanchier laevis 241 



44. Fruits not racemose; pome 1-5 celled 45 



45. Mature carpels papery or soft-cartilaginous 46 



45. Mature carpels hard and bony, forming nutlets in fruit 



Crataegus pedicellata 243 

 46. Fruit pyriform or subglobose; flesh with stone cells. . . .Pyrus communis 231 



46. Fruit globose or depressed globose 47 



47. Fruit g of an inch or less in diameter, bright red 4S 



