Anatomie und Entwicklung der Blasenhaare von Chenopodium-Arten

Abstract

Species from the genus Chenopodium carry various types of hairs: Bladders are restricted to the subgenus Chenopodium , glandular hairs to the subgenus Ambrosia , additionally articulated hairs do occur in both taxa. Two types of bladders are distinguished: 1) Bladders with one glandlike stalk cell and a big bladder cell. They are structured identically with those in Atriplex species. 2) Bladders with a small bladder cell and several vacuolized stalk cells which at no stage of development show any glandular character. On young leaves the glandlike bladders form several layers, the other type of hairs occurs in lower density and is accompanied by articulated hairs. The basipetal development of bladders is restricted to the youngest leaves, so highest hair density is found near the shoot tip. Decreasing- hair density on older leaves does not only depend on the expansion of leaves, but also on the increasing number of bladders formed on younger leaves. Furthermore, two types of glandular hairs are described: 1) Hairs with a vacuolized stalk and a small, glandular outmost cell which contains secret granula, but no chloroplasts, and no central vacuole. 2) Hairs with a big outmost excretion cell and some glandular stalk cells containing a lot of plastides. Their structure shows a striking functional parallelity to glandlike bladders.