CRUCIFERAE 



MUSTARD FAMILY 



ROCK CRESS 



Arahis lyrata L. 



The Rock Cress grows in rocky and sandy places. It^is 

 likely to be found, therefore, in any of those places in the state 

 where there are rock outcrops or sandy soil. It is widely dis- 

 tributed, being found in suitable situ- 

 ations from Ontario to Connecticut, 

 Virginia and Tennessee, southwest to 

 Missouri and northwestward through 

 Manitoba and British Columbia to 

 Alaska. It is also found in Japan. 



The plant has a fleshy taproot that 

 lives through at least one winter, as in 

 the more northern parts of its range it is 

 biennial, and perennial farther south. 

 The solitary or several stems grow 4-12 

 inches high and usually are somewhat 

 hairy toward the base but occasionally 

 entirely smooth. There is a cluster of 

 basal leaves, often several times the 

 number shown, which may be hairy or 

 smooth. 



The number of flowers on each stem 

 varies greatly. The 4 yellowish green 

 sepals are small but the pure white 

 petals are longer and quite conspicuous. 

 There are the usual 6 stamens, 2 

 shorter than the others, and i pistil 

 with a short slender style. The fruit 

 is a pod containing 2 rows of seeds. 



The Sicklepod, Arabis canadensis L., is a perennial 2-4 feet high, 

 mostly unbranched, with numerous lanceolate leaves barely toothed 

 or entire and sessile or nearly so. The small greenish white flowers 

 are in terminal or lateral racemes. They are followed by flat green 

 pods lyi-Jt inches long and curved, which remain after the leaves 

 have fallen and then open from below by the 2 elastic valves. 



The Bank or Smooth Rock Cress, Arabis laevigata (Muhl.) Poir., 

 is abundant on steep, shaded, wooded bluff^s throughout. It is 2-4 

 feet tall, smooth and covered with a bloom. The lanceolate or linear 

 stem leaves are mostly toothed and are attached by arrow-shaped 

 clasping bases. The oblong-linear petals of the small greenish white 

 flowers are scarcely longer than the calyx, and the long narrow pods 

 are recurved-spreading on generally erect f)edicels. 



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