270 



NATURAL HISTORY OF PLANTS. 



orbicular glandular disk, with entire or crenulate margin, sometimes 

 smooth and bare on the upper surface, and sometimes supporting a 

 central and conical rudiment of a gyna^cium. Outside of this are 



inserted caducous petals, equal 

 •^ m number and alternating 



with the teeth of the calyx, 

 and an equal, double, triple 

 or quadruple number of sta- 

 mens, arranged in verticils 

 and formed each of a free 

 slender exserted filament, and 

 a short, bilocular, introrse 

 anther dehiscing by two longi- 

 tudinal clefts. In the herma- 

 phrodite flowers, the perianth 

 and androecium are the same ; 

 but the receptacle is deeply- 

 depressed to an obconical or 

 tubular cavity which encloses 

 an inferior and unilocular 

 ovary ,^ surmounted by a simple or rarely bifurcate, curved or revo- 

 lute style, the internal margin of which is traversed by a longitudinal 

 furrow with edges covered with stigmatic papillsB. In the female 

 flowers the stamens disappear, or are carried, in small number and 

 sterile, above the ovary, by the margin of the receptacle. In the 

 internal angle of the ovarian cell near the summit is inserted a 

 descending anatropous ovule, with micropyle exterior and superior. ^ 

 The fruit is an oblong drupe, crowned by a scar, with thick and hard 

 putamen, compressed or cylindrical, enclosing a seed the membranous 

 coats of which cover a fleshy albumen, which envelopes an embryo 

 with foliaceous cotyledons, nearly equal in size to the albumen and 

 surmounted by a short cylindrical radicle. Tupelos consists of trees 

 or shrubs, not unfrequently covered with a silky down, growing, to 

 the number of half a dozen species,^ in the southern part of North 

 America, in the temperate mountainous regions of Asia, and in the 



Fig. 241. Male floriferous branch. 



^ Now and then flowers occur with two car- 

 pels and an ovary with two cells complete or 

 incomplete and uniovulate. 



2 With double envelope. 



3 MiCHX. Arbr. For. t. 18-22.— A. Gray, 

 Man. ed. 5, 201.— Chapm. Fl. S. Unit. St. 168. 

 For the real number of species to be retained 

 see p. 279, n. 6. 



