Cauloid
Cauloid describes the stem of plant-like organisms that are not vascular plants (so-called "lower plants" or thallophytes ). It carries the leaf-like organs ( phylloids ) and is similar to the stem axis of the plants, but has a simpler structure.
Cauloids occur in leafy mosses and are also called "trunks" there.
Cauloids are also found in algae with an articulated thallus , for example in chandelier algae or some brown algae . The highly developed Laminariales have cauloids made of different tissues , a distinction is made between a closure tissue , a cortical tissue and a medulla . The growth in thickness takes place in the inner layers of the final fabric and creates annual rings in perennial stems. The outer cells of the bark ensure the strength of the stem and are also photosynthetically active. The cell walls of the inner bark become slimy and make the stem pliable. Substances are stored in the central marrow. Special trumpet cells serve to transport substances and correspond in their function to the sieve tubes of the vascular plants (an example of convergence ).
The cauloids of the Laminariales can reach considerable dimensions: for example in the giant kelp up to 45 meters and in Nereocystis luetkeana up to 35 meters.
swell
- Peter Sitte, Hubert Ziegler, Friedrich Ehrendorfer, Andreas Bresinsky: Strasburger, textbook of botany. Gustav Fischer, Stuttgart, Jena, New York 1991, ISBN 3-437-20447-5 , p. 234, p. 600, p. 617 and p. 647.
Individual evidence
- ↑ Wolfram Braune: Marine algae. A color guide to the common benthic green, brown and red algae of the world's oceans . Ruggell: Gantner, 2008, ISBN 978-3-906166-69-8 , pp. 202-207.