368 NATURAL HISTORY OF PLANTS. 



From the above it may be seen that very few of the character's 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 

 Rubiece, the woody consistence " of the stem is also ordinarily the rule. 



Geogbaphical distribution.— Of all the genera of Rubiacm 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 

 Rubiece are often plants of temperate and cold countries. Rubia 

 (Galium) Aparine 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 borealis 

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

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

 Black Elder (Sambucus nigra) and Danewort {8. Ebulus) 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 creuelate in some rare species of cularly in the dialypetalons flowers. 

 Uragoga, Carlemannia and Silvianthus, Neuro- * Partly free in the Gcertnerem Flatycarpum, 

 calyx, Beterophyllaa ; lohed in Pentagonia ; Sgnaptantha, Folypremum, Ehachicallis, Mitreola, 

 sinuate, it is said, in Siekingia ; often divided some Oldeiilandias, &c. 

 or compound in the LoniceretB, Samtiecete and in 7 Nil or thin in the true Guettardea. 

 Adoxa. ' Herhaceous also in -Polyprenrnm, Synaptan- 



^ Generally wanting in the old Order of Ca- tha, many Oldenlandiaa, several Uragogaa, a 



prlfoUacem (except in Pentapyxis and many oonsiderahle numher of Medyotide-m and Aiitho- 



SanihucecB), and in several Hedyotidea (in their speimece. Besides Madder and the Cinchonas, 



mode of development and their signification, see several woody Subiacem have heen anatomically 



Laness. Compte Send. Ass. Frang. v. 466, t. 6). studied : Paderia (H. Mohl, Ueb. den Saw der 



There is also a long discussion by LinDLey on Sank.-und Schlingpjl. [1827] ■ § 75), Sabieea 



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



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



' Polypetalous in several Morindem, Aulaco- the tubeioua stems oi Mydnophytum aiii Myrme- 



discus, Synaptantha, Sec. codia, the enlargements of which are hollowed 



* Irregular in PLatycjrpum, Capirona, Ferdi- into cavities inhabited by ants, &c. Several 



nandusa, Dicfiilai.the, and several Loiiicerece Euiiacem are epiphytal or (?) parasitic. 

 (Zmicera, Triosteum, Linncea). 



