KEY, BASED UPOK FRUIT. 9 



e 2 . Small, ovoid-lanceolate pods arranged in catkins, opening by two valves and 

 containing numerous seeds furnished with silky down; leaves 



Orbicular-ovate, unequally dentate 18. POPULUS GRANDIDENTATA. 



Ovate, closely serrate, whitish and reticulate-veined beneath. 



47. POPULUS BALSAMIFERA. 



Deltoid, serrate-dentate ... .48. POPULUS MONOLIFERA. 



Linear-lanceolate, tomentose on midrib above and petiole. 



45. SALIX NIGRA. 

 Lanceolate or elliptic-lanceolate, smooth above. 



46. SALIX ALBA, var. VITELLINA. 



2 . Aggregated Fruit composed of many carpels, either closed or open and coher- 

 ing or closely massed together, forming a cone. 

 6. Scales of the cone open carpels (Coniferce). 



c. Scales many, persistent and spreading at maturity, each subtended by a bract; 



ovules 2, inverted. 



(/, Maturing the year after flowering (Pinus). 



e. Cones ovoid pyramidal, about 2 inches long, carpellary scales thickened 

 at the apex and 



Smooth (unarmed) 19. PINUS RESINOS. 



Armed with a recurved prickle 50. P. RIGIDA. 



e 2 . Cylindric, 4-6 in. long, scales thin and unarmed 49 P. STROBUS. 



(V. Maturing the first season the autumn after blossoming. 



e. Ovoid or oblong, | in. long, pendent; bracts inconspicuous; scales per- 

 sistent on the axis, thin and with eroded tip 20. ABIES NIGRA. 



e*. Ovoid, small (8 lines or less), pendent, scales rounded and entire at tip. 



21. ABIES CANADENSIS. 

 e 3 . Cylindrical, large (2-4 in.), erect; bracts conspicuous, exserted; scales 



falling from the axis at maturity 22. ABIES BALSAMEA. 



e 4 . Ovoid or roundish, small, 9 lines or less, scales persistent on the axis at 



maturity ... 23. LARIX AMERICANA. 



e 2 . Scales few, persistent, bractless; ovules 2-8, erect; cone oblong with oblong 

 loosely imbricated scales somewhat thickened at the tip; seed winged all 

 round 24. THUJA OCCIDENTALS. 



6 2 . Scales 3-lobed bracts each subtending 2-3 closed, indehiscent carpels minia- 



ture samarae (Setula). 



Cones erect, short, scales thin and with barely spreading lobes, wings of 



seed not broader than the body 17. B. LUTEA. 



Cones suberect, ovoid-oblong; scales thicker and with short divergent lobes, 



wing not broader than the body 44. B. LENTA. 



Cones pendent, scales glabrous and with short divergent lobes; wing of 



seed much broader than the body 43. B. PAPYRACEA. 



6 3 . Scales closed carpels, growing from an elongated receptacle and consolidated 



together. 



c. Dehiscent at maturity along the medium line of the back, and letting out 

 each 1-2 berry-like seeds suspended by extensile threads (Magnolia). 



1. M. ACUMINATA. 



c 2 . Indehiscent at maturity and falling away as samarae. 



2. LlRIODENDRON TULIPIFERA. 

 2 



