CLAYTONIA. 43 



shingles on a roof, i. e., are imbricated (imbrex, a tile).* A 

 special mode of imbrication is seen in the petals, of which 2 

 are wholly within, 2 wholly without, and 1 is partly both, 

 having one edge within and one without. This is the quin- 

 cuncial aestivation and very common. 



The Name, Claytonia, was given by Linnaeus to this 

 plant in honor of John Clayton, who sent it to him, in 1757, 

 from Virginia. Hence this species is called C. Virginica. 

 Another species was first seen by Michaux, about 1800, in 

 the mountains of N. Carolina and so named C. Caroliniana. 

 But it is far more common northward from New England to 

 Wisconsin. You may know it by its leaves being shorter 

 and broader elliptic-lanceolate. What other differences do 

 you find ? 



The Order. The Claytonias belong to the same order 

 with the splendid flowering Portulacas, viz. PORTULACACE^B, 

 or the PURSLANES. That troublesome weed of the gardens 

 the common Purslane, is also a species of the genus Por- 

 tuldca P. olerdcea. Its small yellow flowers appear in 

 Summer, and its curious seed-boxes in September. These 

 open by a lid crosswise, and bear the classic name of pyxis 

 (a box. Fig. XLIII, 5). In some countries Purslane is es- 

 teemed as a pot-herb, and a salad, on account of its cooling 

 antiscorbutic properties (Lindley}. 



Classification. In contrast with Erythronium, the 

 genus Claytonia, and its order, by their 2-lobed embryo, and 

 their flowers 5-parted (or at least not 3-parted), represent the 

 EXOGENS, the other province of the Flowering Plants (p. 33). 



Scientific Terms. Estivation. Albumen. Centripetal inflo- 

 rescence. Herbaceous. Imbricated. Introrse. Opposing stamens. 

 Pedicel. Pyxis. Quincuncial. Raceme. Rachis. Sessile. Tuber. 



* In other plants the sepals or petals may he found to meet edge to edge. Such 

 aestivation is called valvate. Indeed the valves of the capsule of this plant thus meet 

 While closed (8). See other modes of aestivation described in p. 80. 



