484 NATURAL HISTORY OF PLANTS. 



Thus the variable characters by which we separate the series of 

 this group are as follows : the structure of the seed, the number and 

 direction of the ovules, the number of carpels, the presence or 

 absence of the perianth, the form of the floral receptacle, and the 

 characters of the vegetative organs. The points by which the genera 

 are distinguished in the several series are, in CMoranthea, the herma- 

 phrodism or dicliny of the flowers, the presence or absence of a floral 

 bract in the males, and the depth of the receptacle and organization 

 of the perianth in the females. In Saururece : the independence or 

 union of the carpellary leaves, the adnation or independence of the 

 floral bracts, the number of parts in the androceum and gynaeceum, 

 the form and depth of the floral receptacle. In Piperece : the de- 

 hiscence of the anthers (into two valves or four), and sometimes the 

 number of divisions of the style, and lastly the structure of the 

 stems. Earely has such a character as the last been used in char- 

 acterizing the tribes of an order, and this just proves its importance 

 here. Long since was the attention of botanists called to the histo- 

 logical organization of the Pipereee by their peculiar habit, their 

 often sarmentose branches with prominent articulated nodes, by the 

 insertion of the leaves, and the development of adventitious roots on 

 certain parts of their stems. 1 Moldenhauer 2 noticed in 1812 that 

 certain species have neither pith nor medullary rays. Since then it 

 has been shown 3 that in the herbaceous stems and branches the fibro- 

 vascular bundles are irregularly scattered through the cellular mass, 

 as in many Monocotyledons. When the axes become woody a 

 regular sheath of wood forms in the second year or vegetative season, 

 surrounding the parenchymatous mass in which the first fibro- 

 vascular bundles are isolated. Then in time the woody zone thickens, 

 and is enlarged with new elements. Finally, " in the arborescent 



. In roost -P^j-** where they occur they 3 Dutebn . j Unters _ ueb . Keim _ rf> M 



2™5 T tbe tl n ? des - . \*W? Cubeba and 23, t. l.-K., in Mem. Mus., iv. (1818), 442 



mos 1° r n ir P1 'T r d f el °P ment « demerit. ™b. d. Fam. d. Piperaa\ m Linnaa 



Si 3 tlU. r °, ' r Tmed ° f a hemi " < 1839 )< 561 ■> in A ™- So. Nat., ser. 2, xiv. 



MS? Stlng ° Ut tLr ° llgh a 173 )- E - Mey -> » e Soultuynia atque Saurur. 



base of tl e petiole Ks^V* ^ ^ f the (1827 >' 38 > ***■ 5-B-Bi., V J la Struct. 



cessor Lr in- from « m ; ede «**°r and sue- des Poivres (in Mem. Soc. Sc. Batav., xi. (1826), 



?2SE5£ r S brl h S aUernat ' 10n i ehrK » p 63 -TH E T 1E ., Ays. a. Gel,, i. 210.- 

 \ Beitr. m. Anat. d. P/ (1812) 5 not YEN " **■«"*%«. »■ 332 - 



