CROCIFEEAB 17 



ascend. Racemes 1 to 3 Inches long, sometimes proliferous. Petals white, Of 

 ochroleucoup, cuneate-obovate, about twice as long as the calyx. 

 Hob. Shaded springs ; Brandywine : not common. Fl. May. Fr. June. 



Obs. My excellent friend, Prof. TORREY, finds it difficult to believe 

 that our Chester County plant is the same as MICHAUX'S: But I 

 have a number of specimens from MICHAUX'S locality (the mountains 

 of N. Carolina), which I am very confident my friend would be puz- 

 zled to distinguish from ours. 



3. C. rli ombo idea, DC. Stem erect, mostly simple; lower 

 leaves oval or rhombic-oblong, on long petioles, upper ones lance- 

 oblong, sessile ; root tuberiferous. 

 RHOMBOID CARDAMINE. Spring-Cress. 



Stem 9 to 18 inches high. Racemes 2 to 5 inches long. Petals white, conspicuous, 

 3 or 4 times as long as the calyx. 

 Hob. Along swampy rivulets : frequent. FL April. Fr. June. 



3O. DE1VTA V RIA, L. 



[Latin, Dens, dentis, a tooth ; from its tooth-like tubers.] 

 Sttique compressed, lanceolate, acuminate. Seeds in a single series, 

 ovate, not margined ; funiculus dilated ; cotyledons thick. Perennials. 



1. D. laciniata, Muhl. Leaves in threes, subverticillate, deeply 

 3-parted; segments lance-linear, laciniate. 

 LACINIATE DENTARIA. Cut-leaved Tooth-wort. 



Rhizoma fleshy, tooth-shaped, moniliform. Stem 6 to 12 inches high, simple. 

 Leaves usually 3, near the summit of the stem, each mostly 3-parted to the base; 

 segments 2 to 4 inches long. Raceme terminal, loose, at first corymbose. Ftowers 

 pale purple, or nearly white. 

 Hob. Kich woodlands : frequent. Fl. April. Fr. June. 



31. AR'ABIS, L. 



[Supposed to have been so named for an Arabian species.] 



Silique long, linear, compressed; valves flattish, 1-nerved. Seeds in 



a single series, oval or orbicular, often margined. Cotyledons flat. 



f Seeds not margined. 



1. A. lyrata, L. Radical leaves lyrate-pinnatifid, hairy ; stem- 

 leaves spatulate-linear, entire, smoothish ; siliques rather spreading, 

 pointed with a short style; radicle often oblique. 



Sisymbrium arabidoides, Hook. Bor. Am. and Fl. Cestr. ed. 2. P. 



387. 



LYRATE ARABIS. American Rock-Cress. 



Perennial f Stem 6 to 12 inches high, branched, often several from the same 

 root. Radical leaves numerous and tufted, 1 to 3 inches long, often dying early 

 and disappearing. Racemes 2 to 5 inches long. Flowers white, rarely tinged with 

 purple. 

 Bab. Dry, rocky hills; Serpentine ridge, abundant. Fl April. Fr. May. 



ft Seeds partially margined. 



2. A. hirsftta, Scop. Hirsute; stem-leaves oblong or lanceolate, 

 clasping and often sagittate; siliques erect, style very short, cla- 

 vate. 



HIRSUTE ABABIS. Hairy Rock-Cress. 



2 



