I4 6 CRUCIFERAE. [Vol.. II. 



31. STENOPHRAGMA Celak. OEster. Bot. Zeitsch. 27: 177. 1877. 



Annual or perennial herbs with the aspect of some species of Arabis, pubescent with 

 forked hairs, with branched slender erect stems, entire or toothed leaves and small white 

 flowers in terminal racemes. Style very short; stigma 2-lobed. Siliques narrowly linear, 

 the valves rounded, nerveless, dehiscent. Seeds in i row in each cell in the following 

 species, in some European species in 2 rows; cotyledons incumbent. [Greek, narrow septum. J 



About 10 species, natives of Europe and Asia. 



i. Stenophragma Thaliana (L.) Celak. Mouse-ear-, or Thale-cress. 



Wall-cress. (Fig. 1770.) 



Arabis Thaliana L,. Sp. PI. 665. 1753. 



Sisymbrium Thalianum Gay, Ann. Sci. Nat. 7: 399. 1826. 



Stenophragma Thaliana Celak. OEster. Bot. Zeitsch. 27: 177. 

 1877. 



Stem slender, erect, i / -i6 / high, freely branching, 

 more or less pubescent with short stiff hairs, especially 

 below. Basal leaves \'-i f long, obtuse, oblanceolate or 

 oblong, narrowed into a petiole, entire or slightly toothed; 

 stem-leaves smaller, sessile, acute or acutish, often 

 entire ; pedicels very slender, spreading or ascending, 

 2"-4" long in fruit; flowers white, about i^ x/ long; petals 

 about twice the length of the sepals; pods narrowly linear, 

 4"-ic/' long, acute, often curved upward, glabrous. 



In sandy fields and rocky places, Massachusetts and south- 

 ern Ontario to Minnesota, south to Georgia and Missouri. 

 Very common eastward. Naturalized from Europe. Native 

 also of northern Asia. April-May. 



32. ARABIS L. Sp. PI. 664. 1753. 

 [TURRITIS L. Sp. PI. 666. 1753.] 



Annual or perennial, glabrous or pubescent herbs, with entire lobed or pinnatifid leaves 

 and white or purple flowers. Siliques linear, elongated, flat; valves smooth, keeled or 

 ribbed, mostly i -nerved, not elastically dehiscent at maturity. Stigma 2-lobed or nearly 

 entire. Seeds in I or 2 rows in each cell, flattened, winged, margined or marginlcss; cotyle- 

 dons accumbent [Name from Arabia.] 



A genus of about 80 species, mainly natives of the northern hemisphere. In addition to the 

 following, about 26 other species occur in the northern and western parts of the continent. Called 

 also Wall-cress. 



Seeds in i or a incomplete rows in each cavity of the pod. 

 Basal leaves pinnatifid; pods ascending. 



Seeds large, orbicular, wing-margined; stem-leaves pinnatifid. i. A. Virginica. 



Seeds minute, oblong, wingless; stem-leaves entire, or dentate. 2. A. lyrala. 



Leaves small, mostly entire ; pods drooping; seeds oblong, wingless; arctic. 3. A. numi/usa. 

 Basal leaves merely dentate or lyrate. 



Seeds minute, oblong, wingless. 4. A. denlata, 



Seeds larger, oblong, winged or margined. 



Pods curved upward, nearly i" broad. 5. A. alpina. 



Pods nearly erect, %" broad. 



Flowers white, 4" broad; pods not appressed; style 1 A" long, 

 Flowers white or greenish-white, 2" '-3 +"*** ~' <.>,, 



6. A. patens. 

 broad; pods appressed; style none. 



7. A. hirsula. 

 Pods recurved-spreading. 



Plant glabrous throughout. 8. A.laevigata. 



Leaves and lower part of stem hairy. 9. A. Canadensis. 



Seeds in 2 distinct rows in each cavity of the pod. 



Pods spreading or ascending; seeds winged. 10. A. brachycarpa. 



Pods erect, appressed; seeds wingless or narrowly winged. n. A. glabra. 



Pods reflexea; seeds winged. 12. A. Holboellii. 



