YELLOW GROUP 



Woods and thickets, dry or moist soil. The species are 

 difficult to separate. 



Wild Senna 



Cassia marilandica. — Family, Pulse. Color, bright golden 

 yellow, growing paler. Leaves, compound, of 8 to 10 pairs of 

 oval leaflets. July and August. The papilionaceous type of 

 corolla is lost here. The petals, 5 in number, are unequal, 

 open and spreading, large, made more conspicuous by the 10 

 stamens of different lengths, with their large, dark-brown, almost 

 black anthers. No tendrils or odd leaflets terminate the pinnate 

 leaves. A small club-shaped gland marks the joining of each leaf 

 to the main stem on the upper side of the leaf. The flowers ter- 

 minate the branches in short axillary racemes. The corolla drops 

 off easily, and a specimen gathered for the herbarium must be 

 quickly dried. It grows 3 to 5 feet high, a handsome plant, with 

 slender, hairy pods, 3 inches long, following the blossoms. 



Collected and dried, the pods and leaves form the Ameri- 

 can senna used in medicine. New England to Florida and 

 westward. 



Partridge Pea 



C. Chamaecrisia. — Color, bright yellow. The spreading petals, 

 not papilionaceous in character, are unequal in size. 2 or 3 have 

 a purple spot at the base. Stamens, 10, 4 with yellow anthers, 

 6 with purple, all opening by 2 pores at the apex. Pod, flat, 

 many-seeded, with cross-partitions. Leaves, pinnate, from 10 to 

 15 pairs of leaflets, and one terminal, all somewhat sensitive, 

 folding together when plucked. A pair of cup-shaped glands is 

 found at the base of the 2 lowest leaflets. Stipules, present. The 

 showy flowers, on slender pedicels, grow in small clusters under 

 the leaves. Stems, erect, but spreading, about r foot long. Late 

 summer. 



Dry, sandy soil, especially near the seashore, Massachu- 

 setts southward and in the interior. 



Wild Sensitive Plant 



C. nictitans. — This species bears very small flowers, on short ped- 

 icels, similar in shape and size to the last. Leaflets, 10 to 20 pairs, 

 oblong to linear, sensitive, with a gland at the base of the petiole. 



Shelley's famous poem, "The Sensitive Plant," refers to 

 the Mimosa pudica, a European plant, whose leaves are more 

 sensitive than those of our cassias. All of this genus fold 

 their leaflets and "sleep" at night. In the partridge pea 

 each pair folds together, and they then lie along their main 



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