368 NATURAL HISTORY OF PLANTS. 



From the above it may be seen that very few of the characters are 

 absolutely constant ; but that several are so frequent and are wanting 

 only in cases so exceptional that they impress upon the family a very 

 decided mark. These are in particular : the opposition of the entire 

 leaves/ the presence of stipules;^ the gamopetalousness of the corolla,^ 

 its regularity ;* the insertion of the stamens upon it ; ^ the inferior 

 ovary ^ and the presence of an albumen in the seeds.' Except in the 

 BiihiecB, the woody consistence ^ of the stem is also ordinarily the rule. 



Geographical distribution. — Of all the genera of Ruhiacece we 

 have admitted, twenty-two only are found in both worlds. America 

 possesses exclusively seventy- eight ; the old world a hundred and 

 twelve, about half the total. Many of the genera, it is true, are 

 monotypes, particularly in tropical Africa and Madagascar. The 

 Ruhiece are often plants of temperate and cold countries. Ruhia 

 (Galium) Apariiie is found throughout Europe, in Asia, in Africa and 

 in America, from the extreme north to Tierra del Fuego. Many of 

 the annual Galiums are found everywhere in the crops. Linncea horealis 

 grows in the north of Europe, Asia and America. Many Caprifoliece 

 are plants of the cold regions of the northern hemisphere. The 

 Black Elder (Samhucus nigra) and Danewort (S. Ehulus) are found as 

 far as Sweden. Adoxa is very widely spread throughout the northern 

 hemisphere. With the exception of Mitchella, which ascends to the 



^ Alternate in Didymochlamys and Adoxa ; ° Sometimes inserted on the receptacle, parti- 

 dentate or crenelate in some rare species of cularly in the dialypetalous flowers. 

 Uragoga, Carlemannia and Silvianthus, Neuro- ^ Partly free in the GcertnerecB Platycarpum, 

 calyx, Seterophyllcea I lobed in Pentagonia ; Synaptantka, Polypremum, Rhachicallis, Mitreda^ 

 sinuate, it is said, in Sickingia ; often divided some Oldenlandias, &c. 

 or compound in the Lonicerece, Sambucece and in 7 Nil or thin in the true GuettardecB. 

 Adoxa. 8 Herbaceous also in Polypremiim^ Synaptan- 



2 Generally wanting in the old Order of Ca- tha, many Oldenlandics, several Uragogas^ a 



prifoliaceoe (except in Pentapyxis and many considerable number of Hedyotidece and Antho- 



SaiihucecB), and in several Stdyotidece (in their spermeoe. Besides Madder and the Cinchonas, 



mode of development and their signification, see several woody RubiacecB have been anatomically 



Laxess. Compte Eend. Ass. FraiK^. v. 465, t. 5). studied: Fcederia (H. Mohl, TJeb.den Bau der 



There is also a long discussion by Lindley on Rank.-und Schlingpjl. [1827] § 75), Sabicta 



the value of the stipules of the GaliacecB in the (Crueg. Bot. Zeit. [1851] 470). Mention has 



Vegetable Kingdom (769). often been made of the singular organization of 



^ Polypetalous in several Morindtce, Julaco- the tvLberoua atems of Syd/iophytum and My/me- 



discus, Synaptantha, &c. codia, the enlargements of which are hollowed 



■* Irregular in PLatycirpum, Capirona, Ferdi- into cavities inhabited by ants, (fee. Several 



nandusa, Dichila.Me, and several L'uiicerece Uttdiacece are epiphytal or (?) parasitic. 

 {^Lvdcera, Triosteum^ Linncea). 



