Evolutionary history of plants phloem on the outside. Since xylem cells comprise dead, lignified tissue, subsequent rings of xylem are added to those already present, forming wood. The first plants to develop secondary growth and a woody habit, were apparently the ferns, and as early as the Middle Devonian one species, "Wattieza", had already reached heights of 8 m and a tree-like habit. Other clades did not take long to develop a tree-like stature. The Late Devonian "Archaeopteris", a precursor to gymnosperms which evolved from the trimerophytes, reached 30 m in height. The progymnosperms were the first plants to develop true wood, grown from
Botanical Garden named after Rostovtsev Botanical Garden named after Rostovtsev The Botanical Garden named after S. I. Rostovtsev () is a Botanical Garden in Moscow at the Timiryazev Agricultural Academy. Founded in 1895 on the initiative of botanist S. I. Rostovtsev. The garden area is about 1.2 hectares. The Botanical Garden is part of the complex reserve "Petrovsko-Razumovskoye" and has the status of a specially protected natural area of federal significance. The founder of the botanical garden S. I. Rostovtsev will divide it into 3 departments: systematic, biological and experimental. In the systematic department, students studied the systematics of plants. The biological department was designed