Senega From False Senega. Soak suspected root in water until soft (10 hours), make thin cross-sections: true senega root has irregular, porous, yellowish wood; false senega root has cylindrical, porous, whitish wood. The irregularity of the structure of the cortex of senega (true) is well brought out by staining with haematoxylin solution. See pages 361, 364.
Taraxacum From Chicory. Make thin cross-sections as before: taxaracum shows in the bark laticiferous ducts in many brown circles; chicory has these vessels arranged radially. The location of the laticiferous ducts is revealed readily by staining with hematoxylin, as they assume a darker color than the other cells on account of the dense coagulated contents of the duct. Both have deposits of inulin (which is related closely to starch) in the soft cells, which stains yellow with iodine. See pages 593, 595.
Calumba From Bryonia. Calumba shows thick bark, small wood-bundles bright yellow, distant near the centre, in narrow rays near the bark, medullary rays broad, parenchyma filled with starch; bryonia has thin bark, cork thin, friable, wood-bundles small, numerous, in rays and concentric circles, surrounded by thin-walled parenchyma. See pages 211, 590.
Belladonna From Inula. Belladonna has thickish bark, no bast-fibres, wood-bundles central, small, distinct, surrounded in the thicker roots by broader wood-wedges, and equally wide medullary rays; inula has a broad bark of small cells, radially arranged, with a distinct light circle of cambium between the bark and the wood area, which latter is made up of a large proportion of soft cells radially arranged and many large wood-vessels in rows. Both in the bark and the wood area there are many large openings of resin-ducts. Inula contains inulin deposited as spheres in the cells, while belladonna has much starch over the whole section. See pages 521, 602.
Ipecac From Spurious Ipecacs. Ipecac has quite a regular bark of isodiametric cells containing starch; some of the cells contain oxalate raphides (needles), particularly in the inner bark. The wood is radiate, with medullary rays hardly distinguishable from the wood-cells in shape, but containing starch-grains. False roots have thick bark, no starch. See pages 551, 557.
Pareira From False Pareiras. Pareira has thin bark, wood in several concentric circles, waxy cut, wood-wedges porous, uniform, numerous, separated by wavy circles of waxy parenchyma-tissue resembling medullary rays, stem with central pith. False roots have hard wood in eccentric circles, fresh cut not waxy. See page 215.