The leaves of monocots with their parallel venation are mechanically strengthened by a number of sclerenchyma bundles that render them extremely tension-proof. The sclerenchyma bundles of many monocot leaves are of economic importance (sisal, hemp [Agave sisalana], New Zealand flax [Phormium tenax]). The picture shows such a bundle within the surrounding, softer parenchyma. This tissue type resembles reinforced concrete constructions. (W. BARTHLOTT, 1983 unpublished)