422 PATAGONIAN EXPEDITIONS I BOTANY. 



KEY TO THE GENERA. 



A. Hairs simple or none. No glandular hairs nor glandular tubercles. 



b\. Style long. Silicic winged, its cells i -seeded. Leaves pinnatifid. Flowers white. 



I. Menonvillea, p. 424. 



b2. Stigma equally developed on the style, capitate. Silicic on a gynophore ; its mericarps 

 winged on the margins and mid-nerve, i -seeded. Septum narrow ; radicle lateral on 

 cotyledons. Flowers white. 2. Hexaptera, p. 424. 



3. Stigma strongly developed above the placentae ; more or less 2-lobed, or depressed in 



the notched pod. 



c\. Cotyledons starting below the bend of the embryo. Silicles basally rounded to cor- 

 date, its cells i -seeded, seed pendulous. Lateral and median honey-glands. Sta- 

 mens sometimes 4 or 2, or more than 6. Radicle usually dorsal. 

 d\. Silicic 2-valved, with lanceolate or elliptic septum. Petals white, rarely yellowish 



or none. 3. Lepidium, p. 425. 



d2. As Lepidium, but stamens 6 ; cells of silicle communicating by chinks, and leaves 



minute, imbricating. 4. Delpinoella, p. 427. 



dz. Silicle indehiscent, broader than long, didymous, its septum linear. Petals white, 

 rarely purple or none. 5. Coronopus (Senebiera), p. 427. 



c2. Cotyledons starting at the bend of the embryo. 



til. Silicle winged all round, septum narrow; or a i-2-seeded schizocarp. Cotyle- 

 dons not folded ; radicle lateral. Only lateral honey-glands. Calyx not gib- 

 bous. Petals white, rarely pink. 6. Thlaspi, p. 428. 

 d2. Fruit a silique, rarely a silicle ; sometimes transversely segmented, or a 1-2- 



seeded schizocarp. Usually both lateral and median honey-glands. 

 ei. Style more or less lobed, or depressed. 



f\. Embryo with dorsal radicle and flat or arched or longitudinally folded 

 cotyledons. Silique long, 2-valved, with numerous, i-( rarely 2-) 

 seriate globose, wingless seeds. Style short, 2-lobed. Median honey- 

 glands. Flowers yellow, rarely white or pink. Leaves entire, or 

 toothed, or pinnately lobed. 7. Sisymbrium, p. 429. 



f2. Embryo with the cotyledons longitudinally folded. Siliques, sometimes 

 transversely segmented, with erect seeds, and mostly a soft septum in 

 the distal segment. Flowers racemose. Median honey-glands. 

 g\. Seeds all pendulous ; or distal seeds erect, but not in a specially 

 enlarged segment. Silique with an apical, not flattened, rostrum. 

 Cotyledons conduplicate. 



hi. Silique dehiscent; its seeds i -seriate, globular or slightly com- 

 pressed. Cotyledons 2-lobed. Flowers yellow or white to 

 violet. 8. Brassica, p. 432. 



ft2. Silique dehiscent, constricted between the seeds, but not jointed. 



Petals white or yellow. 9. Raphanus, p. 433. 



g2. Seed solitary in a special apical segment, enlarged before anthesis ; the 

 normally barren proximal part of the silique resembling a gynophore. 

 Cotyledons 2-lobed ; radicle dorsal. Petals white. 



10. Crambe, p. 433. 



