GLOSSARY 317 



Recurvatus (recurvare = to bend backwards). Curved 

 back. 



Reflexed (reflectere = to bend back). Bent back. 



Repens (Lat. repere = to creep). Applied to creeping 

 plants. 



Resin Canals or Resin Ducts. Intercellular spaces running 

 parallel with the stem and through the leaf. In a trans- 

 verse section of the leaf they take the form of a circular 

 opening which is visible under a magnifying glass, or can 

 be sometimes sufficiently made out by squeezing the 

 leaf after it has been cut across, when the resin can be 

 discerned exuding from the ducts. They are differently 

 placed and vary in number in different trees. Some- 

 times they are situated close to the edge or the epidermis 

 of the section of leaf, and then are described as marginal. 

 In other trees they are placed about half-way between the 

 centre of the leaf (where the fibro-vascular bundle is 

 seen), and the outside edge, when they are described 

 as median. For example, the resin canals in the Common 

 Silver Fir are two in number and marginally placed. In 

 the Douglas Fir the same, while the P. Laricio (Corsican 

 and Austrian) have eight mediajily placed resin ducts. 

 The Hemlock spruces have only one placed close to, and 

 immediately under, the fibro-vascular bundle. In the 

 Temate (3-in-a-bundle) Pines and the Ouinse (5-in-a- 

 bundle) the resin canals are usually fewer. 

 These are some of the more minute characteristics of conifers 

 that ought to be studied in the transverse section under 

 magnifying glasses. 



Reticulatus (reticulum = a little net). With small inter- 

 secting Hues like the meshes of a net. 



Revolute (re = back ; volvere = to roll). Rolled back out 

 of the ordinary direction. 



Rhomboid (Gk. rhembein = to turn round and round). An 

 imperfect oval-shaped figure and angular at the middle, 

 and so a form more or less diamond-shaped. 



Scales. An expression connected with the word Shell, and 

 used to denote the scales or thin layers and coverings of 

 a fish or reptile. Applied botanically to the encrusted 

 covering of leaf buds and cones. 



