HISTOLOGY OF PHLOEM IN WOODY ANGIOSPERMS 377 
Carya cordiformis 
Fig. 9. Tangential section, mature stem, showing lattice in face view and sieve 
plates in section. X 100. 
Juglans cinerea 
Fig. 10. Resting cambium, mature plant, showing shape of cells in tangentia 
section. X 100. 
Fig. II. Tangential section taken in the phloem near the cambium showing 
division of cambium cells to form parenchyma and sieve tubes. The sieve-tube 
elements are of the same length as the cambium cells. X 100. 
Fig. 12. Transverse section of one-year stem showing small sieve tubes and 
abundant parenchyma. X 100. 
Juglans nigra 
Fig. 13. Transverse section of two-year root showing increase in size and 
number of sieve tubes as compared with one-year material (fig. 12). X 100. 
Fig. 14. Transverse section of four-year stem showing increase in size and 
number of sieve tubes as compared with two-year material (fig. 13). X 100. 
Juglans nigra 
Fig. 15. Transverse section of mature stem. Note series (figs. 12-15). X 100. 
Ulmus americana 
Fig. 16. Radial section showing transverse sieve plates with slime strings 
adhering to them. X 250. 
Fig. 17. Tangential section showing sieve tube with transverse sieve plate and 
well-developed lattice. X 270. 
Madura pomifera 
Fig. 18. Radial section of mature stem showing transverse sieve plates. X 250. 
Morus alba 
Fig. 19. Radial section showing transverse sieve plates. X 270. 
Eleagnus angustifolia 
Fig. 20. Tangential section showing single, transverse, or oblique sieve plates 
and lattice. X 250. 
Liriodendron Tulipifera 
Fig. 21, Mature stem, transverse section. Sieve tubes in lower part near 
cambium are partially occluded with callus. X 100. 
Fig. 22. Mature root, transverse section. Note much smaller amount of 
sclerenchyma as compared with stem. X 100. 
Fig. 23. Radial section showing large sieve plates in face view upon the end 
walls and smaller well-developed plates on the side walls. X 180. 
Fig. 24. Radial section, mature root, showing variation in size of sieve plates 
upon end and side walls. X 200. 
Fig. 25. Same, tangential section showing sieve plates in section and close 
contact of sieve tubes, parenchyma, and medullary rays. X 125. 
