Dicotyls or Exogenous Plants. 57 



Ar'-a-bis can-a-den'-sis L. Sickle-pod. — Stem upright, smooth 



above; steam-leaves pubescent, pointed at both ends, sessile, the lower 



toothed; pods very flat, scythe-shaped, hanging on rough, hairy 



pedicels. 



t 



A. Seeds not so bruad as the paylition, in tcvo more or less distinct i-oivs in each 



cell ; erect and leafy-stemnted plants. 



Ar'-a-bis per-fo-li-a'-ta Lam. Tower Mustard.— Tall, 2-4 ft. high, 

 glaucous; stem-leaves oblong or ovate-lanceolate, entire; petals yel- 

 lowish white, little longer than the calyx. 



Ar'-a-bis brach-y-car'-pa (T. & G.) Britt. {A. conjinis Wats.) Rock 

 Cress. — Scarcely glaucous, l-.'j ft. high, pubescence below finely stel- 

 late ; stem-leaves lanceolate or oblong-linear, 1-2 in. long, entire, with 

 narrow auricles, or the lowest spatulate and toothed ; petals white or 

 rose-color, fully twice the length of the calyx. 



A. Seeds oblong or elliptical, very small ; plants branching from the base. 



Ar'-a-bis ly-ra'-ta L. Rock Cress. — Mostly glabrous except the lyrate 

 ' pinnatifid root-leaves ; stem-leaves spatulate or linear with a tapering 

 base, sparingly toothed or entire; petals white, much longer than the 

 yellowish calyx. 



Ar'-a-bis den-ta'-ta T. & G. Rock Cress. — Roughish pubescent, 

 slender, 1-2 ft. high ; leaves oblong, very obtuse, unequally and sharply 

 toothed, those of the stem numerous, half-clasping and eared at the 



XXXIII. Order SAX-I FRA-GA'-CE-/E. SAXIFRAGE FAIMILY.^Herbs 



or shrubs ; leaves opposite or alternate ; stamens mostly definite and 

 with the petals on the calyx. 



Herbs a; 

 Shrubs b) 

 a. Ovary 2;rarely 3;-celled, or with 2 or 3 nearly distinct carpels b . 

 a. Ovary 1-celled, with 2 parietal placentas c . 



b. Petals •"), stamens o Sjillivantia. 1 



b. Petals ."), sta:nens 10 Saxifraga. 2 



c. Petals entire, stamens 10 Tiarella. 3 



c. Petals small, entire, stamens 5 Henchera. 4 



c. Petals small, pinnatifid, stamens 10 Mitella. .5 



c. Petals none, stamens 8-10 Chrysosplenium. 6 



d. Leaves opposite, frnit a capsule Hydrangea. 7 



d. Leaves alternate, fruit a berrv Ribes. 8- 



