CRUCIFEROUS TRIBE a; 



17. Nasturtium (Cress) 



1. A^. officinale (Common Water-cress).- Leaves pmnate ; leaflets 

 roundish or oblong, toothed ; flowers white. Abundant in rivulets 

 and ponds, and extensively cultivated as a salad. The only plant 

 for which it can be mistaken by water-cress gatherers is the Procum- 

 bent apium, which may be distinguished by its hollow leaf-stalks 

 and serrated leaflets, which water-cress has not. — Fl. June to 

 August. Perennial. 



2. N. sylvestre (Creeping Yellow Cress). — Leaves pinnate ; root 

 creeping ; stems ascending ; flowers small, yellow ; petals longer 

 than sepals. Watery places, not common. — Fl. June to Sep- 

 tember. Perennial. 



3. A'', palustre (Marsh Yellow Cress). — Not so large as the last, 

 and petals smaller. Found in similar places, but more frequent. 

 — Fl. June to November. 



4. A^. amphibiitm. Larger than any of the foregoing. Flowers 

 yellow ; petals longer than the sepals. Banks of streams and wet 

 places, not common. — Fl. June to August. Perennial. 



18. Sisymbrium [Hedge Mustard) 



1. 5. officinale (Common Hedge Mustard). — 

 T?ods downy, close pressed to the stem ; leaves 

 hairy, deeply lobed, with the points turned 

 backward, the terminal lobe large ; stem rough, 

 with erect branches, 1-2 feet high ; flowers 

 small, yellow. Common in waste places and by 

 roadsides, where it seems to have a peculiar 

 aptitude for collecting and retaining dust. 

 — Fl. June, July. Annual. 



2. 5. Lrio (London Rocket).— Leaves pinnately OFrraNlLE 

 lobed, with the points turned backward, toothed, {Common Hedge 

 smooth ; stem also smooth, erect, branched, about Mustard) 



2 feet high ; flowers small, yellow. A local plant, 

 growing in waste ground, chiefly about London, where, in the 

 spring following the Great Fire of 1666, it -sprang up very plenti- 

 fully among the ruins, whence its English name. 



3. 5. Sophia (Flixweed). — Leaves twice pinnatifid, downy ; 

 petals shorter than the calyx. More slender than either of the pre- 

 ceding, with an erect branched stem about i foot high ; and small 

 greenish yellow petals, which are almost hidden by the calyx ; and 

 numerous erect pods, which when ripe have the appearance of being 

 bearded, from the numerous projecting seeds. Waste places and 

 roadsides, not uncommon. — Fl. summer. Annual. It was called 

 by the old herbalists Sophia chiriirgoriim, " the Wisdom of Sur- 

 geons," from its supposed virtue in curing wounds. 



