400 DICOTYLEDONES. 



the otherwise prevailing correspondence with the Fumariaceaa. Yet it may he 

 observed that in special cases each pair of long stamens clearly enough arises 

 from one protuberance and even later on may be considerably united or entirely 

 undivided (e.g. Velio) ; in other instances they are quite distinct from the 

 beginning, and it is possible that this latter condition has become constant in 

 the corolla. Lepidium ruderale and others have no corolla. Senebiera didyma 

 has only 2 median stamens. Megacarpcea has several stamens, no doubt by 

 dedoublement, as in Capparidacea?. The number of carpels may also be 

 abnormally increased ; Tetrapoma barbareifolium has normally 4 carpels with 

 an equal number of placentae and repla. It is supposed to be a variety of 

 Nasturtium palustre. The 2-4-8-10 greenish glands, which are found at the 

 base of the stamens, are nectaries, morphologically emergences, and not rudi- 

 mentary stamens. The forms of fruits are of great systematic significance, see 

 the genera. In some species dimorphic fruits are present, e.g. Cardamine 

 chenopodiifoU* which has both ordinary Cardamine-siliq\iQ,a and 1-seeded 

 siliculas. 



The curved embryo appears in five forms, which have systematic importance : 

 1. To the PLEUEOBHIZ^E belong those genera whose radicle (with the hypocotyl) 

 lies bent upwards along the edge of the flat cotyledons (Fig. 399) ; to this group 

 belong Cardamine, Nasturtium, Cheiranthus, Matthiola, Cochlearia, Drabti, 

 Iberis, Thlaspi, etc. ; diagrammatic transverse section : Q 2. To NOTO- 

 RHIZ.E belong those whose radicle lies in an upward direction along the back of 

 one of the flat cotyledons (Figs. 400, 413) ; e.g. Hesperis, Sisymbriitm, Lepidium, 

 Capsella, Camelina: Q [|. 3. OBTHOPLOCE^E differ from the Notorhizeaa in 

 having the cotyledons folded (not flat) (Fig. 398 E, f) ; to this belong Bras- 

 sica, Sinapis, Raplianus, Crambe, etc. : Q^X 4. SPIBOLOBE^E : the radicle lies 

 as in the Notorhizae, but the cotyledons are so rolled together that a transverse 

 section of the seed cuts them twice ; Bunias : Q II II- 5. DIPLECOLOBEJE : the 

 cotyledons are folded forward and backward so that a transverse section cuts 

 them several times; Subularia, Senebiera : O II II II- 



On germination the cotyledons appear above the ground as 

 green leaves ; in the Orthoploceae they are bilobed, in the' Lepidium- 

 species divided. 



1. Silicula, broad replum (Siliculosse latiseptse), valves flat 

 or slightly vaulted, and the replum extends through the greatest 

 width of the silicula (Fig. 404). The seeds are situated in two rows. 



O : Cochlearia (Horse-radish) : the siliqua is nearly spheroid ; 

 glabrous herbs, generally with fleshy, stalked leaves, and white ' 

 flowers. Drdba has an oblong, lanceolate, somewhat compressed 

 silicula ; herbs with small rosettes of leaves, most frequently with 

 stellate and long-stalked racemes. Alyssum and Berteroa are 

 whitish, on account of the stellate hairs ; they have a more com- 

 pressed and round or elliptical silicula. Vesicaria ; Aubrietia. 

 Lunaria (Honest}^, Fig. 401): very broad and flat silicula with 

 long stalk (the receptacle as in Capparidaceae). 



