47 



59a. Petals conspicuous, about twice as long as the calyx, or longer; 



straight, erect, mostly unbranched plants 60. 

 59b. Petals inconspicuous, equaling or but little longer than the 



calyx 61. 



60a. Pods 3 4 cm. long, ascending (summer) 



Rock Cress, Arabis patens. 

 60b. Pods 8 10 cm. long, recurved (late spring) 



Eock Cress, Arabis laeyigata. 



Gla. Pods widely spreading; stem usually sparingly branched near 



the base (spring) Kock Cress, Arabis dentata. 



61b. Pods erect or appressed; stem usually unbranched (summer) 



62. 

 62a. Stem-leaves and stem smooth and glaucous 



Rock Cress, Arabis glabra. 



62b. Stem-leaves and stem almost always pubescent, and never 

 glaucous Kock Cress, Arabis hirsuta. 



3a. Principal stem-leaves 1 10 cm. long, or more 64. 

 63b. Principal stem-leaves 2 5 cm. long 65. 



64a. Leaves lanceolate or oblong; flowers 10 mm. wide or less 

 (37 dm. high; summer) Kock Cress, Arabis cauadensis. 



64b. Leaves ovate or ovate-lanceolate; flowers 15 20 mm. wide 

 (5 8 dm. high; late spring and summer) 



Dame's Kocket, Hesperis matronalis. 

 5a. Basal leaves ovate to orbicular or cordate, not more than twice 



as long as broad (1 3 elm. high; spring) (Bitter Cress) 66. 

 65b. Basal leaves oblong, lanceolate, or oblanceolate, at least 3 times 

 as long as broad (13 dm. high) 67. 



66a. Flowers purple or rose color 



Bitter Cress, Cardamine douglassii. 

 66b. Flowers white Bitter Cress, Cardamine bulbosa. 



67a. Basal leaves pinnatifid (spring and summer) 



Rock Cress, Arabis lyrata. 



67b. Basal leaves entire or toothed 68. 



68a. Leaves narrowly oblanceolate; rare plant occurring from 

 Mackinac northward (summer) Rock Cress, Braya humilis 

 68b. Leaves obovate or oblong; an introduced weed (spring) 



Mouse-ear Cress, Sisymbrium thalianum. 



CAPPARIDACEAE, the Caper Family 



Herbs, with alternate compound leaves, 4 petals, and 6 or more 

 stamens, which are about equal in length; fruit a 1-celled pod. 



One species in Michigan, stamens about 11; leaflets 3 (2 4 dm. 

 high; flowers yellowish, in summer) 



Clammy-weed, Polanisia graveolens. 



