18 



THALAMIFLOR^ 



16. Barbarea (Winter Cress). Pod linear, 4-angled ; valve* 

 with prominent nerve ; seeds in a single row ; calyx erect. (Name 

 from St. Barbara, to whom it was anciently dedicated.) 



17. Nasturtium (Cress). Pod nearly cylindrical, short ; valves 

 :onvex, nerveless ; seeds irregularly placed in two rows ; calyx 

 spreading. (Name from nasus tortus, a distorted nose, on account 

 of the pungent properties of the plant.) 



18. Sisymbrium (Hedge Mustard). Pod rounded or angular ; 

 valves convex, with 3 (or rarely 1) nerves ; stigma entire ; seeds in 

 a single row ; seed-stalks slender. (Name, the Greek name of the 

 plant.) 



19. Alliaria (Garlic Mustard). Pod long, linear, rounded ; 

 valves slightly 3-nerved ; seeds striated ; seed-stalks flat. (Name 

 from the Latin, allium, garlic.) 



20. Erysimum (Treacle Mustard). Pod 4-sided ; valves keeled ; 

 stigma obtuse, entire or notched ; seeds in a single row, smooth, 

 not margined. (Name from the Greek, eruo, to cure, on account 

 of the supposed virtues of the plant.) 



21. Cheiranthus (Wall-flower). Pod flattened ; valves with a 

 prominent nerve ; stigma of two spreading lobes. (Name of 

 Arabic origin.) 



22. Matthiola (Stock). Pod nearly cylindrical, or flattened ; 

 stigma of two erect parallel lobes ; seeds generally with a mem- 

 branous border. (Named in honour of Dr. Matthiolus, an Italian 

 botanist.) 



23. Brassica (Cabbage). Pod nearly cylin- 

 drical, beaked ; seeds globose. (Name from the 

 Celtic, bresic a cabbage.) 



Pod without valves 



24. Raphanus (Radish). Pods swollen, im- 

 perfectly jointed, tapering ; seeds globular ; calyx 

 spreading. (Name in Greek, denoting early ap- 

 pearance or quick growth.) 



I. Thlaspi (Penny Cress) 



I. T. arvense (Mithridate Mustard, or Penny 

 Cress). Pouch round, flat, with very broad wings 

 and a deep notch ; leaves oblong, arrow-shaped 

 at the base, toothed, smooth. Height about a 

 foot. In cultivated or waste ground, but not 

 common. Penny Cress derives its name from the 

 Thi.aspi Arvense resemblance which its seed-vessels in size and 

 (Penny 0*) shape bear to silver pennies : its longer name is 



