I 7 8 



CRUCIFERAE. 



VOL. II. 



32. IODANTHUS T. & G. ; A. Gray, Man. 32. 1848. 



A glabrous erect perennial herb, with dentate leaves auricled at the base, or the lower 

 and basal ones lyrate-pinnatifid, and violet or white flowers in panicled racemes. Sepals 

 much shorter than the petals, the inner ones slightly gibbous at the base. Petals long-clawed. 

 Styles stout; stigma subcapitate. Silique linear-cylindric, slightly compressed, somewhat 

 constricted between the seeds. Seeds oblong, rounded, in I row in each cell. Cotyledons 

 accumbent. [Greek, violet-colored flower.] 



A monotypic genus of southeastern North America. 



i. Iodanthuspinnatifidus(Michx.) 



Steud. Purple or False Rocket. 



Fig. 2068. 



Hesperis ( ?) pinnatifida Michx. Fl. Bor. 



Am. 2:31. 1803. 

 lodanthus hesperidoides T. & G. ; A. Gray, 



Gen. 111. i: 134. 1848. 

 Thelypodium pinnatifidmn S. Wats. Bot. 



King's Exp. 25. 1871. 

 lodanthus pinnatifidus Steud. Nomencl. Ed. 



2, 812. 1841. 



Glabrous, stem slender, i-3 high, 

 branching above. Lower leaves ovate or 

 oblong, occasionally cordate, 2'-8' long, 

 dentate, tapering into a margined petiole 

 which is clasping and auriculate at the 

 base, the lower part of the blade often 

 pinnatifid into 2-6 pairs of small oblong 

 segments; stem-leaves similar or merely 

 dentate, narrower, sometimes ovate- 

 lanceolate, the upper nearly sessile; flow- 

 ers numerous, 3"-4" broad; pedicels 

 spreading, 2"-$" long in fruit ; pods 

 linear, |'-ii' long, i" wide, spreading or 

 ascending; style stout, i" long. 



On river banks, western Pennsylvania to 

 Minnesota, south to Tennessee, Missouri, 

 Louisiana and Texas. May-June. 



ARABIS L. Sp. PI. 664. 1753. 

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



Annual, biennial or perennial, glabrous or pubescent herbs, with entire lobed or pin- 

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

 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 marginless; cotyledons 

 accumbent. [Name from Arabia.] 



A genus of about 120 species, mainly natives of the northern hemisphere. In addition to the 

 following, about 35 other species occur in the northern and western parts of the continent. Type 

 species : Arabis alpina L. Called also Wall-cress. 



Seeds in i row or 2 incomplete rows in each cavity of the pod. 

 Basal leaves pinnatifid ; pods ascending. 



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

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

 Leaves small, mostly entire ; pods drooping ; seeds oblong, wingless ; arctic. 

 Basal leaves merely dentate or lyrate. 

 Seeds minute, oblong, wingless. 

 Seeds larger, oblong, winged or margined. 

 Pods curved upward, nearly i" broad. 

 Pods nearly erect, y 2 " broad. 



Flowers white, 4" broad ; pods not appressed ; style J /i" long. 



33- 



1. A. virginica. 



2. A. lyrata. 



3. A. arcnicola. 



4. A. dentata. 



5. A. alpina. 



6. A. patens. 



Flowers white or greenish-white, 2"-^" broad ; pods appressed ; style none. 



Seeds wing-margined ; plant not glaucous. 

 Seeds wingless ; plant glaucous. 

 Pods recurved-spreading. 



Plant glabrous throughout. 

 Leaves and lower part of stem hairy. 

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

 Pods spreading, erect or ascending ; seeds winged. 

 Pods erect ; basal leaves glabrous or nearly so. 

 Pods spreading ; basal leaves stellate-pubescent. 

 Pods reflexed ; seeds winged. 



Basal and lower leaves loosely long-pubescent ; pods blunt. 

 Basal and lower leaves finely stellate-pubescent ; pods acute. 



7. A. hirsuta. 



8. A. glabra. 



g. A. laevigata. 

 10. A. canadensis. 



1 1. A. Drttmmondii. 



12. A. brachycarpa. 



1 3. A. Holboellii. 



14. A. Collinsii. 



