Class XXIII. Order I. 377 



Leafets about five pairs, with an odd one, nearly sessile, ovate, 

 ncute, with slight vesicular serratures, somewhat downy under- 

 neath. The flowers appear in April and May before the leaves 

 are expanded. They grow in sessile umbe!-j about the origin of 

 the young branches, are small and greenish. I have observed 

 them of three kinds, making the shrub strictly polygamous. In 

 the staminiferous flower, the calyx is five leaved, leaves oblong, 

 obtuse, erect. Stamens five, with subulate filaments and sagit- 

 tate four celled anthers. In the place of the pistils are three or 

 four roundish corpuscles supported on pedicels from a common 

 base. The perfect flowers growing on the same plant have the 

 calyx and stamens like the last ; the germs are three or four, 

 pedicelled, and having erect, converging styles nearly as long as 

 the stamens. The pistiiiferous flowers grow on a separate shrub. 

 Calyx smaller and more compressed. Germs about five, pedi- 

 celled ; styles converging into close contact at top, and a little 

 twisted. Stigmas obtuse. All the flowers are destitute of co- 

 rolla. Each fertile flower produces an umbel of as many stipi- 

 tate capsules as there were germs in the flower. These capsules 

 are oval, covered with excavated dots, varying from green to 

 red, two valved, one seeded ; seed oval, blackish. Woods, Med- 

 ford. April, May. Perennial. 



The rind of the capsules has an agreeable lemon like scent. 

 The bark is pungent, and is used in rheumatism. 



438. ACER. 



ACER RUBRUM. Li. Sivamp Maple. Red Maple. 



Leaves palmate-five lobed, unequally toothed, pu- 

 bescent, and at length glaucous underneath, the sinuses 

 acute ; fertile flowers aggregate, with rather long 

 stalks. Mich. 



This maple grows plentifully in our swamps and low woods. 

 The flowers appear in April and May, each bud producing a 

 fascicle or sessile umbel of about five crimson flowers. In the 

 barren flowers the calyx is about five parted with oval segments. 

 Petals five, narrower arid inflected. Stamens twice as long as 

 the calyx. Perfect flowers on separate trees, later and smaller, 

 the stamens included ; styles two, exserted, recurved, pubes- 

 48 



