ordeh 119.— the MASTWORTS. 279 



b Involucre none. Anthers 4-valved. Leaves lobed. Sassafras. Sas'safras. 1 

 b Involucre 4 leaved. Anthers 2-valved. Shrubs. Spice-bush. Ben'zoin. 



b Involucre 4-leaved. Antliers 4-valved. Shrubs. S. Pond-spice. Tetuan'thera. 



SASSAFRAS. Sassafras. 

 Flowers dioecious, G-parted, regular. Stamens 9. Trees with decidu- 

 ous leaves, expanding after the clusters of yellow flowers. 

 S. officina'le. Common S. Leaves of two forms, ovate and entire, or S-lobed and 

 acute at base. Tree aromatic, 10-30f. high. 



Order CXIX. CUPULIFERJi:. The Mastworts. 



Trees or shi'uls, with alternate, simple leaves, and deciduous stipules; 

 powers monoecious, the sterile in aments, which are racemed or head-like ; 

 stamens in the sterile flowers, 6 to 20, on the base of the calyx; 

 ovajy in the fertile flowers with several cells and ovules, but becoming in 

 f?'uit a 1-seeded nut surrounded by an involucre (cup, burr, or sac). 



Analysis of the Genera. 



% Sterile flowers in aments, fertile flowers solitary or 2 or 3 together 2 



§ Sterile flowers and fertile also in aments, the latter loose and large c 



2 Involucre 1-ttowered, cup-like, composed of many little scales a 



2 Involucre 2 or 3-flowered, composed of few large valves b 



« Sterile aments slender, calyx 5-cleft, stamens 5 or 10. Fertile flowers, con- 

 sisting of an ovary sitting in a scaly cup, becoming, in fruit, an acorn, 1- 

 celled, 1-seeded. A noble genus of trees (rarely shrubs), always known by 

 their peculiar fruit, called acorns. The timber is of great value, especially 

 in ship-building. In the Class Book of Botany, 23 species are described. 

 (See Figs. 32-34, 267.) Oak; Quercus. 



b Involucre of the fruit and fertile flowers a burr with 4 valves. Sterile aments 

 slender, each flower with 5-15 stamens ; 3 fertile flowers in each involucre, 

 -which is beset with slender prickles. We have two species, one a tree, the 

 other a shrub. Timber excellent. The fruit is sweet and nutritious. (See 

 Fig. 277.) Clieistnut. Casta 'nea. 



b Involucre of the fruit a burr with 4 valves. Sterile aments head-like, sus- 

 pended by a slender stalk. Calyx 6-cleft. Two flowers in each burr, which 

 is covered by weak spines. Nuts sharply 8-angled. They are tall, valua- 

 ble forest-trees. Betch. Fag us. 



b Involucre a sac, longer than the nuts, torn at the top. Sterile flowers in a 

 slender ament. Shrubs. Usually but one flower or nut iu each involucre. 



llazfl. Cou'yi.ob. 



