57 



RONDELETIA 



Rondeletia L. Rubiaceae (r. 3). 60 warm Am., W.I. 

 Ronnbergia E. Morr. et Andre. Bromeliaceae (4). 2 Colombia. 

 Root, the organ for absorption from the soil (in most cases); adven- 

 titious -, see Adv. Root ; aerating -, aerial -, see Aer. and Aer. 

 Roots ; apogeotropic -, Bo-venia ; - as suckers, see Parasites ; - as 

 tendrils, Vanilla; -as thorns, Acahthorhiza; -as tubers, Bravoa, 

 Dahlia, Dioscorea, Paeonia, Thladiantha, Uragoga ; bitter -, Lewi- 

 sia; buttress -, Pahnae, Pandanaceae; -cap, Lemua, Panda ni/s ; 

 - climbers, see Climbing PI. ; fibrous -, in tufts of uniform length, 

 as in a grass ; - hairs, the absorbing hairs near the tip of a root ; 

 paint-, Lachnanthes; parasitic -, see Parasites; Par eira -, white, 

 Abnta ; -rubber, Carpodinus, Clitandra ; -stock, an erect, short rhiz., 

 as in many ferns; true -, the result of the radicle of the embryo; 

 waterplant -, see Water PI. 

 Ropalocarpus Boj. Tiliaceae. 3 Madag. 

 Ropourea Aubl . Verbenaceae (inc. sed.). i Guiana. 

 Roridula L. Droseraceae. 2 S. Afr. Like Drosera, but with no 



movement of the leaf-tentacles. 



Roripa Scop. (Nasturtium R. Br. p.p.). Cruciferae (2). 50 ^_. 

 Rosa Tourn. ex L. Rosaceae (in. 6). 100 N. temp, and on trop. 

 mts. ; 6 in Brit., incl. R. canina L., the dog-rose. The thorns are 

 epidermal appendages. The fl. of R. canina is a pollen fl. The 

 fr. (hip) consists of a number of achenes enclosed in the fleshy recept. 

 which closes over them after fert. R. centifolia L. is the form from 



which the cabbage rose is derived ; and numerous forms of this and 



other sp. are cult, (see Nat. PJJ.}. Otto of rose is distilled mainly 



from R. damascena Mill., cult, in the Balkans. [E. Willmot, The 

 genus Rosa, London 1914; Baker, Revised Classification of Roses in 

 Journ. Linn. Soc. 35, 1905, p. 70.] 

 Rosaceae (EP. ; BH. incl. Euciyphiaceae). Dicots. (Archichl. Resales). 



100 gen., -2000 sp., cosmop. Trees, shrubs and herbs, usu. perenn. ; 



1. alt. (exc. Rhodotypos), simple or cpd., 



usu. slip., the stipules often adnate to the 



petiole. Veg. repr. in various ways, but 



esp. by creeping stems runners as in 



strawberry, or suckers as in raspberry. 



Fls. term., in racemose or cymose infls. 



of various types ; great variety of forms. 



Receptacle generally hollowed, so that 



various degrees of perigyny occur. Fre- 

 quently there is a central protuberance 



bearing the cpls., even in the forms with 



very much hollowed recept. In a few 



cases (subfams, II, IV) the cpls. are united 



to the recept, and fully inf. The recept. 



often forms a part of the fr. Fl. usu. 5 



and actinom. K 5, often with an epicalyx 



of outer and smaller 1. (see Potentilla), 



usu. imbr.; C 5, usu. imbr. ; A 2, 3 or 4 times as many as 



petals, or oo , bent inwards in bud ; G usu. apocarpous and sup., 



rarely syncarpous or inf. ; cpls. as many or 2 or 3 times as many as 



st 



floral Diagram of Potentilla 

 fruticosa (after Eichler). 

 ep. = epicalyx, st. = stipules 

 of bracts and bracteoles. 



