RETINISPORA 561 



Resins, products of secretion or disintegration, usu. formed in special 

 cavities or passages; collected by tapping. Insoluble in waier, 

 soluble in alcohol, ether, or carbon Bisulphide; burn with a sooty 

 flame. Roughly divisible into hard resins proper, gum-resins or 

 mixtures of gum and resin, and baharns, fluid resins or resins dis- 

 solved in ethereal oils. Resins are derived from the distillation ol the 

 turpentines of Coniferae, &c., the hard copals or animes from Agathis, 

 Hymenaea, Trachylobium, &c., the dammars from Canarium and 

 other Burseraceae, Shorea and other Dipterocarpaceae, Drncaena, 

 Guaiacum, Protium, Rhus, Xantliorrhea, &c. Gum-resirs from Bos- 

 \vellia (frankincense), Calophyllum, Convolvulus, Dorema, Ferula, 

 Garcinia (gamboge). &c. Balsams from Burseraceae (esp. Canarium), 

 Commiphora, Coniferae (turpentines), Copaifera (balsam of Copaiba), 

 Dipterocarpus, Liquidambar, Melanorrhoea, Myroxylon (balsam of 

 Peru, Tolu), Opoponax, Pistacia (Chian turpentine, mastic), Populus, 

 Styrax, Valeria, Vatica ; - passages, channels in which resin 

 flows. 



Respiration, absorption of O and evolution of CO 2 ; cf. Aerenchyma. 



Rest harrow, Ononis. 



Restans (Lat.), persistent. 



Restiaceae (/?//.) = Restionaceae. 



Restiaria Lour. Inc. sed. i China. 



Restio L. Restionaceae. no S. Afr., Austr. Assimilation is per- 

 formed by the green stems, the 1. being reduced to sheaths. 



Restionaceae (EP., BH.) Monocots. (Farinosae; Glumaceae BH.}. 

 19 gen., 250 sp., mostly in S. Afr. and Austr., a few in N.Z., Chili 

 and Cochin China. Xero., usu. of tufted growth, with the general 

 habit of Juncus; below ground is a rhiz. with scaly 1. , giving off erect 

 cylindrical shoots bearing sheathing 1. (rarely with ligules), which 

 have a short blade, or sometimes none, in which case assim. is per- 

 formed by the stem. Fls. dioec. (rarely monoec. or $ ), r^g-i m spike- 

 lets. P in two whorls, but single members often absent ; A 3 or i, 

 opp. to the inner perianth-1.; G (3 i), i 3-loc., with i pend. orthotr. 

 ov. in each. Caps, or nut. Embryo lens-shaped, in mealy enclosp. 

 Chief genus: Restio. 



Restrepia H. B. et K. Orchidaceae (n. 8). 15 trop. Am. 



Retama Rafin. = Genista Tourn. p.p. (Legum.). 



Retanilla Brongn. Rhamnaceae. 6 Chili, Peru. 



Retinaculum, Acanthaceae, Asclepiadaceae, Zoste>a. 



Retiniphyllum Humb. et Bonpl. Rubiaceae (i. 8). 10 trop. S. Am. 



Retinispora Sieb. et Zucc. = Thuya L., &c. Seedlings of many sp. of 

 the genera Chamaecyparis, Cupressus, Thuya, &c., exhibit, instead 

 of the decussate appressed 1. of the mature plant, spreading needle-1. 

 (often in whorls of 4) like those of Abies, &c. (cf. Pinus, Acacia, &c.). 

 If now these young seedlings be used as offsets, the new pi. thus 

 formed retain throughout life this form of foliage; and pi. are thus 

 obtained of totally different habit from that usual in these genera. To 

 these 'seedling forms' the name R. was given. Many in gardens. 

 The synonymy of some is: If. decussata hort. = Thuya orientalis ; R. 

 filifera Fowles = Cupressus obtusa; K. jimiperoides Carr. = Thuya 

 orientalis; R. obtusa Sieb. et Zucc. = Cupressus obtusa; R. pisifera 



W. 36 



