UMBELLIFEBJE. 



141 



Mydncotyh asiatica. 



SydrocotyU asiatica. 



same point (fig. 157) terminate each in a small umbel (or false 

 umbel') simple or with' two or several ranks of flowers superposed, or 

 in a compound umbel. ^ This is most generally the case in the true 

 Hydrocotyle,^ which have pointed valvate petals, and fruit with no or 

 very indistinct secondary ridges. In Centella, 

 another subgenus of which a separate genus has 

 been formed, the petals are obtuse, wider, oftener 

 imbricate. The secondary ridges of the fruit are 

 frequently more distinct. In H. asiatica (fig. 

 158-161), which may be considered a type of this 



group, the floral pe- 

 duncles bear only a few 

 flowers, often three, of 

 which one, older, is 

 terminal, accompanied 

 by two bracts in the 

 axil of each of which 

 is a flower of the second 

 generation. It appears 

 then a biparous and 

 three-flowered cyme.* 

 In Micropleura,^ which 

 we make another subgenus, the inflorescences, 

 more or less ramified, bear fertile terminal flowers, 

 and, immediately below, a few younger flowers, 

 mostly sterile, male and pedicellate. ' 



Thus constituted,* the genus Hydrocotyle comprises about seventy 

 species,' mostly aquatic, which belong to all the warm and temperate 

 regions of the globe. 



Fig. 160. Fruit (?). 



Fig. 161. Trana. sect, 

 of fruit ("j»). 



1 The central flower is often older than those 

 which immediately surround it. 



2 Particularly in ff. bonariensis, where not 

 only a common axis terminates in an umbel (?) 

 of small secondary floral groups, but where the 

 pedicels of the umhellules are accompanied by 

 a variable number of solitary flowers inserted 

 at the point of divergence. 



^ Euhydrocoty1eT)C. Prodr.sect. 1. 

 * Apaort from development, it might be con- 

 sidered either a terminal cluster or a biparous 



cyme, in either case three-flowered, but without 

 possible distinction. 



' Lag. Oe. Hsp. Emigr. 15. — DC. Mdm. 71 ; 

 Prodr. iv. 71. — Endl. Gen. n. 4360.— B. H. Gen. 

 873, n. 2. 



6 Sect. 3 : 1. Euhydrocotyle (DO.) ; 2. Cen- 

 tella (L.) ; 3. Micropleura (Lag.). 



7 R. et Pav. pi. Per. t. 245-248.— Cav. Icon. 

 ,t. 488, fig. 1.— Wight, Icon. t. 564, 565, 1002, 



1003.— Link et Ott. Ic. PI. Sar. t. 21.— Hook. 

 Icon. t. 303, 312 ; ErM. Fl. t. 29, 30.— Eeichh. 



