STILLINGIA 391 



of solitary crystals or rosette aggregates, occasionally occurring in 

 the form of short rods, sphaerites, or in the form of V- or W-shaped 

 crystals. Both glandular and non-glandular hairs occur in a num- 

 ber of specific forms. Stinging hairs are also found in a number of 

 tropical genera. 



STILLINGIA. Queen's Root. The root of Stillingia sylvatica 

 (Fam. Euphorbiacese), a perennial herb indigenous to the southern 

 United States. The root is collected in August, deprived of its root- 

 lets, cut into transverse pieces and carefully dried. 



Description. (Fig. 170.) Cylindrical, tapering, and slightly 

 branched, about 40 cm. in length; usually cut into pieces 2 to 10 

 cm. in length, 5 to 30 mm. in diameter; externally dark brown, longi- 

 tudinally wrinkled, rootlets or rootlet-scars few; fracture of bark 

 fibrous; internally, cork, reddish-brown, thin; inner bark light red- 

 dish-brown (when fresh whitish), 0.5 to 4 mm. in thickness, soft, 

 spongy, with numerous resinous-tanniferous cells and easily separable 

 from the porous, radiate wood; odor faint; taste bitter, acrid and 

 pungent. 



Inner Structure. (Fig. 170.) In the thin lateral roots the epi- 

 dermis is soon replaced by a thin-walled exodermis surrounding a 

 cortical parenchyma, consisting of about 5 layers of mostly collapsed 

 cells, which are without starch. The endodermis is thin walled 

 (Fig. 170, H) and the pericambium shows several tangential 

 divisions, giving rise to the cork, which later on forms the protective 

 tissue around the secondary cortex, when the peripheral tissues 

 from epidermis to endodermis become thrown" off. There are in the 

 stele three broad strands of primary leptome, in 1 which many stereids 

 are scattered, a structure which is apparently not present in the other 

 Euphorbiaceous drugs. The hadrome consists of the three primordial 

 rays and generally somewhat wider vessels are developed on the inner 

 flank of the leptome. There is no pith and the conjunctive tissue is 

 but sparingly represented. 



In slightly thicker roots there is a corresponding structure and 

 the leptome here contains very many stereids; on the other hand the 

 secondary leptome is destitute of stereome and is represented by 

 exceedingly narrow strands in the now typical collateral vascular 

 bundle (Fig. 170, 7). 



The thick fusiform roots show a strongly developed cork, con- 

 sisting of thin- walled brownish cells; a cortex of nearly isodiametric, 

 thin-walled, starch-bearing parenchyma, scattered strands of bast 

 fibers occurring singly or in small groups, and reddish-brown tannif- 

 erous cells traversing the secondary cortex; the secondary leptome 



