92 



NATURAL EISTOBY OF PLANTS. 



Fig. 73. Fruit. 



Fig. 74. Trans, sect, of fruit (j). 



Laserpitium (fig. 73, 74) has given its name to a tribe (Laserpitiece) ; 

 we refer it to the preceding types. The fruit is slightly compressed 

 parallel to the commissure, and its primary and secondary ridges are 

 visible. But whilst the primary are linear and little prominent, the 



secondary are developed 

 Laserpitium latifoiium. into entire or dentelatc 



wings, flat or nearly so, 

 especially the marginal, 

 which are ordinarily 

 larger than the dorsal. 

 The seed, in this genus, 

 is flat or sMghtly con- 

 cave on the ventral sur- 

 face. There are a score 

 of species of Laserpitium, perennial herbs, glabrolis or hispid, with 

 leaves, involucres and involucels formed of an indefinite number of 

 linear bracts. They inhabit Europe, northern Africa and western 

 Asia. 



Thapsia (fig. 76, 76) is very near Laserpitium. They are herbaceous 

 and perennial plants. All the ridges of the fruit 

 Thapsia garganica. are linear, except the marginal secondary, which 



are dilated into large membranous wings. More 

 rarely the dorsal also become aliform but re- 

 main much narrower. In the true Thapsia the 

 ventral face of the seed is flat. In Elceoselinum, 

 it becomes concave, with the margins much 

 involute ; so that it is to other Thapsias what 

 Torilis is to Daucus proper. This genus is 

 Mediterranean. Its fruit has vittse only under 

 the secondary ridges. 

 Fig. 75. Fruit (J). PolylopMum, a glabrous perennial herb of 



Persia and the neighbouring regions, has quite 

 the organization of Laserpitium. But the ovoid fruit, dorsally com- 

 pressed, has all the ridges dilated to short, undulate wings, divided 

 and crumpled at the margin. 



In Melanoselinum (fig. 77, 78), native of Madeira and Cape Verd, 

 the stem is often erect and woody, and the inflorescence is furnished 

 with involucre and involucels. The primary ridges are little prominent 

 and the two lateral occupy a portion of the internal face of the 



