210 GLOSSARY OF TERMS AND INDEX TO PART I 
Pressing plants, 36. 
Prickles. Sharp, spine-like elevations on the bark, leaf or fruit, 28. 
Primary root, 10. 
Pubescent. Hairy or downy, especially with fine soft hairs or 
pubescence, 23. 
Pulp. The soft flesh of such fruits as the apple or cherry. 
Punctate. With translucent glands, 23. 
Pyramidal. With sloping sides like a pyramid, but with a circular 
base; broad-conical. ‘ 
Raceme. A flower-cluster with one-flowered stems arranged along 
the peduncle, 26. 
Radial section of wood, 35. 
Radiating ribs. The ribs of a leaf when several start together at or 
near the base. A leaf having such ribs is said to be radiately or 
palmately veined, 20. 
Rapier-shaped. Narrow, pointed, and curved like a sword. 
Recurved or refleced. Bent backward, 28. 
Regular. Said of a flower which has its enveloping organs alike on 
all sides, 25. 
Repand. Wavy-margined, 22. 
Retuse. With a slightly notched tip, 22. 
Revolute. Rolled backward, as the edges of many leaves, 22, 34. 
Ribbed. With prominent ribs, often somewhat parallel. 
Ribs. The strong veins of a leaf, 19. 
Root, 9. 
Rugous. Having an irregularly ridged surface, 23. 
Samara, A winged fruit ; a key fruit, 28. 
Sap-wood, 13. 
Scabrous. Rough or harsh to the touch, 23. 
Seale-shaped, 21. 
Scarious. Thin, dry, and membranous, 23. 
Scattered leaves, 18. 
Secondary roots, 10. 
Section of wood, 35. 
Seedling. A young plant raised from a seed. 
Seeds, 25. 
Sepal. A division of a calyx, 25. 
Serrate. Having a notched edge, with the teeth pointing for- 
ward, 22. 
Serration. A tooth of a serrated edge. 
Serrulate. Finely serrate, 22. 
Sessile. Without stem; sessile leaf, 20; sessile flower, 26. 
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