UMBELLIFER^ 19 



secondary ones, with the ridges at the commissure slender or 

 less often developed into wings, sometimes separating from 

 an axial carpophore, and each one-seeded and indehiscent. 

 The walls of the fruit are always dry, and the outer or exocarp 

 is membranous, crustaceous, or thickened and corky. The 

 seed conforms to the cavity of the cell, to the inner wall of 

 which it is adnate, and is flattened, or longitudinally furrowed 

 or concave along the ventral face, or is altogether free. The 

 testa is thinly membranous ; and the interior is occupied with 

 a copious cartilaginous endosperm. The embryo is small, 

 close to the hilum, often minute, and ovoid, or larger with 

 ovate or linear cotyledons which may be equal or unequal. 

 The radicle also varies somewhat in length, but is usually 

 short and always superior. 



A few exceptional cases occur in the Order, as for instance 

 in Actinotus and Petagnia where the ovary is one-celled, and 

 one-ovuled by abortion, and in Lagoecia which is mono- 

 carpellary. In various species three carpels occasionally 

 appear, while in others, one of the two carpels is imperfect or 

 becomes aborted. The exocarp of Apleura is fleshy, while the 

 endocarp is lignified. The embryo being very small is not of 

 much use in classifying the species of this large Order. The 

 fruits and seeds themselves are however very variable, and 

 although they never attain any great size relatively, their 

 characters are constant, and in systematic classification the 

 form and the flattening, whether dorsal or lateral, the ridges 

 both primary and secondary, and the number of oil cavities 

 or vittse in the interstices are of the greatest importance for 

 arranging the species into tribes and genera. The tribes 

 again are grouped into three primary series according to the 

 characters of the inflorescence, the ridges and the vittse. 



The fruits appear to fall into five groups according to the 

 form of the mericarps, and the seeds they contain. In all of 

 these groups the cotyledons have their backs to the axis, a few 

 only their edges, but these may be considered as exceptions to 

 the general rule, and will be mentioned by themselves. The 

 groups merely represent types with strongly marked cha- 

 racteristics. The first contains those fruits where the meri- 

 carps are more or less distinctly pentagonal. A good type of 



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