112 NATURAL niSTORY OF PLANTS. 



or more frequently in pseudo-corymbs. Seven or eight species are 

 known, from China' and Japan/ India, and the neighbouring 

 countries. We may define them as Dillenias with small flowers and 

 versatile, not adnate, anthers. 



All the BillcniacecB we have enumerated, like the Rantmculaceay 

 possess but few absolutely constant cliaracters in common, and 

 in this order even the number of stamens is not always large and 

 strictly indefinite. But they possess a certain number of other 

 characters, to which their very frequent occurrence imparts a 

 value ; the alternation of the leaves,' the polypetaly of the corolla,' 

 the independence of the elements of the gyna^ceum,* the hy- 

 pogynous insertion of the stamens and perianth," the persistence 

 of the calyx around the fruit/ and the presence of an aril at 

 the base of the seeds.* We should also add that the flower 

 is nearly always quite regular, and that the exceptional irregu- 

 larities observed are usually not constant even throughout the 

 genus, and are limited to a single verticil,' the regularity of the 

 general plan of the flower not being otherwise affected. 



The most striking characters among those which are variable, 

 and are chiefly used to establish the great subdivisions of the Order, 

 are as follows : the independence, or greater or less union of the 

 elements of the gyna^ceum ; the situation, and definite or indefinite 

 number of those of the androceum. The direction of the anthers 

 and consistency of the pericarp are characters so variable that 

 they can only serve to found the ultimate divisions of genera, or 

 even species. 



We learn from R. Brown,'" that the first idea of making a 



' nENTHAM, Fl. IIongTcong., 2G.— Pt., in " Tims the DeHtnas Imvc a single exccntric 



nook. Journ., vi. 3(i3. — Walp., Ann., i. 15. carpel ; but the rest of tiic flower is regular. 



■■' SlEiioi.i) it Zrcf., in AhhandLdn- Akad.d. CerUiin 8i)ocies of Tetracera, Uarilla, &c., have 



Wissensch. Munch., iii. 727, t. ii., f. 2. an irrejjuliir corolla, owing to tlie snppression of 



' In the Jlcmisli-mmas of Madagascar, the some of the j)etals, but the other whorls remain 



leaves tire often opjwsitc. regular. I'leurundra and Schumiuheria, |)0(tt)ti88 



* One /rormia alone is, as it appears, apctalous an irregular androceum, the flower being othcr- 

 (soe p. 109, note 1). wise that of Jlilif/frtia or Tetracera. Never is 



* Dillenin, Wormia, and Actinldia, would bo the irregularity sufticiently deeidinl or extended 

 the only excej)tionH. over a sudicient number of j)arts to give it a 



* Perigjny is slightly indicated in llilherlia generic value. In tin- c^ilyx of 7>(/ri7/rt the irre- 

 (jrosmlariafulia (see p. U t, fig. 131). gularity does not even apjK-ar Ix-fore a certain 



7 Some Aclinid'uu seem to be the only ex- ]>eriud, while the calyx Ntill remains gymnietrical 



ceptions. with regard to a single plane. 



" Actinidia and several Dillcnias have seeds '" (Jen. litmurks on (he liotan. of Trrra 



without any true Jiril. Aualr., 'J. 



