574 RUBIACEAE 



and are frequently united to one another and to the petioles, so that 

 a sheath is formed round the stem. The two slips. one from each I. 

 that stand side by side are usu. united, and in the Galieae, to which 

 the Brit. sp. belong, are leaf-like, and often as large as the ordinary 1. ; 

 a char, appearance is thus produced, the plants seeming to have whorls 

 of 1.; and it is only by noting the axillary buds that a clue is obtained 

 to the real state of affairs. The number of organs 1. and slips. in 

 a whorl varies from 4 upwards, according to the amount of ' fusion ' 

 or ' branching ' of the slips. The simplest case is a w'horl of 6, each 

 leaf having 2 separate slips. ; if the slips, be united in pairs, a whorl 

 of 4 resulls ; if each slip, be branched into Iwo, we gel a whorl of 10, 

 and, if the cenlre pair of half-slips, on eilher side be uniled, a whorl 

 of 8. 



Several are myrmecophilous (cf. Cecropia, Acacia), e.g. Myrme- 

 codia, Cuviera, Duroia, Hydnophytum. 



Infl. typically cymose. Sol. lerm. 

 fls. rare; small dichasia more frequenl; 

 mosl common case a much branched 

 cymose panicle. 



Fl. usu. g , reg., epig., 4- or 5-me- 

 rous. K 4 5, epig., oflen almosl 

 absent, usu. open in aestivation, some- 

 times with one sepal larger lhan Ihe 

 resl and brighlly coloured (Mussaenda, 

 &.c.) ', C (4 5), valvate, conv., orimbr.; 

 A 4 5, all. wilh pelals, epipet; G (2) 

 rarely ( I oo ), 2-1 OC. wilh Ioo analr. Floral diagram of Asperula, 



ov. in each loc.; ov. erecl, pend., or after Eichler. 



horiz. ; style simple; sligma capilale or lobed. Caps, (sepli- or 

 loculi-cidal), berry or schizocarp. Embryo small, in rich endosp. 



Most have conspic. insecl-pollinaled fls. The Brit. sp. have small 

 fls. with freely exposed or slighlly concealed honey, chiefly visiled by 

 flies; many Irop. sp. have bee- and Lepidoplera-fls. with long tubes. 

 Honey usu. secreted by an epig. neclary round base of style. He- 

 leroslylism is common, and dioecism somelimes occurs. 



Several are of economic importance, e.g. Cinchona, which yields 

 quinine, while many of its allies have also valuable alkaloids, Coffea 

 (coffee), Uragoga (ipecacuanha), Rubia, &c. 



Classification and chief genera (after Schumann). The R. are 

 closely allied lo Caprifoliaceae (g.v.) and less nearly lo Compositae, &c. 

 I. CINCHONOIDEAE (ovules oo in each loculus). 

 A. CiNCHOMNAE (fruit dry) : 



a. Fls. solilary or in clecussale panicles. 



a. Fl. regular; seed nol winged; C valvale. 

 i . Candamineeae : Condaminea. 



i. Oldenlandieae : Oldenlandia, Houslonia, Penlas. 



b. As a, but C imbr. or conv. 



3. Rondeletieae : Rondeletia. 



c. As a, but C 2-lipped. 



4. Henriquezieae \ Henriquezia. 



d. As b, but seed winged. 



