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CONTRIBUIÇÃO AO ESTUDO ANATÔMICO DE CURATELLA AMERICANA L.

SUMMARY

The leaf of Curatella americana L. is scleromorphic with anomocytic stoma on the abaxial apidermis and with four types of thick walled cells of wich three are characteristic of the species: a) Long, simple hairs principally on the nerves on tha abaxial side; b) Short hairs formed of a series of cells (up to 20) with short, pointed apical saliences, best developed on the adaxial epidermis; c) Stellate hairs, formed of a series of cells and having a short and a long, slender lateral projection; d) Mixed hairs with short cells, as in the short hairs, and long cells as in the stellate type.

The epidermises are impregnated with silica, the adaxial epidermis being extremely rough.

The palisade tissue is single layered but frequently is subdivided, and on the margins of the blade there occurs a well developed collenchyma with chloroplasts.

The midvein has epidermal cells with crest like cuticular saliences, with the 4 types of hairs; the cortical region has collenchyma and parenchyma well provided with chloroplasts and a sheath of long-celled, sclerified parenchyma which completely surrounds the vascular bundles and which has chloroplasts. The phloem and xylem form continuous or nearly continuous circles. The medular parenchyma has some subsidiary vascular bundles, grouped, spherical sclereids and large quantities of raphides of calcium oxalate.

The petiole, with decurrent blade, has a structure similar to the midveins, but the slerfied parenchyma is absent or nearly absent. The epidermal cells are papillose and can appear to be 2-4 times divided forming simple trichome-like assemblages or with dichotomous or lateral branches.

Fresh cuts of the rachis and petiole reveal great quantities of needle-like crystals of calcium oxalate, as well as the presence of much tanin in the tissues when the reaction tests is made with 10% ferric chloride.

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