Summary
The following paper is a profile of the Magnolia tree, and it addresses its background, origin, and biological attributes. It will examine the life cycle of the tree in addition to its reproductive system, and carry out a study on the plant’s evolutional history. Under evolution, it will focus on the various adaptive traits the plant has developed over the years and their importance. It will also mention a few unique attributes that make the plant different from other angiosperms.
Introduction
The Magnolia tree is also called the Southern magnolia or bull bay, its scientific name is Magnolia Grandiflora, and it is classified under the Kingdom Plantae, Order Magnoliales, the Magnoliaceae family, and Genus Magnolia. It is native to the southern parts of the USA and grows in Virginia, Florida, Texas and Oklahoma States. It also does well in other warm parts of the world, where it is commercially planted because the hard timber makes it ideal for making furniture and pallets.
Life Cycle
The life Cycle of the Magnolias starts with the seeds, which are grown either through cuttings of grafts, they are dispersed by birds or mammals and due to their hard outer cover, they go through the digestive tracts unharmed (Halls, 1977). The next stage is the sapling or pole stage when they are about 3 to 7 inches in diameter and they develop an extensive root system from the single taproot in the seedlings. The Juvenile stage is when they appear mature, but cannot produce flowers or seeds, this can last as few as 10, or as many as 25 years. The flowering stage is when they are mature and produce flowers, which have both male and female parts. Their lifespan is between 80 to 120 years depending on where they are growing.
Reproductive System
Their reproductive system is usually bisexual (perfect), and the flower consists of 3 sepals and between 6 and 12 petals. These are however not very distinct from each other and they are referred to as tepals. The stamen is spiral, and the flowers have many simple ovaries that are centrally placed (Halls, 1977). Insects pollinate the plant, which makes it possible for the differentiation of species through cross-pollination. Double red seeds in each follicle then connect the fruits, which are dispersed by birds and mammals over large distances.
Evolution and adaptation
The Magnolias are some of the oldest angiosperms with some of their fossils estimated to be over 90 million years old (Soltis, Soltis & Edwards, 2005). While the plant is generally bisexual, there are fossil records that suggest some early species might have reverted to unisexuality. The same has been experienced in other primitive plant families such as the Winteraceae, whose flowers are unisex. Botanists claim that the floral structure evolved to facilitate pollination by beetles since the plant existed before bees did. In addition to beetles, other animals such as primitive moths and even some caterpillar species also facilitated pollination.
Molecular analysis of the Magnolias reveals that the group comprises of six families namely, Myristicaceae, Degeneriaceae, Himantandraceae, Magnoliaceae, Eupomatiaceae, and Annonaceae (Soltis, Soltis & Edwards, 2005). The relationships among members of this family are visible in their shared minimal pit borders, stratification of their phloem and the presence of a progressive tectum within their pollen. In addition, there is a testa capable of multiplication of the seeds, among other distinct similarities.
Additional Information
Magnolia trees have fascinated botanists for centuries owing to their singular features such as the fact that, despite evolving for millions of years, their flower structure has remained almost unchanged. In addition, contrary to popular expectations that evergreens are neat trees, especially for domestication, the Magnolia is particularly messy and it shed leaves and fruits all year round.
References
Halls, L. K. (1977). Southern magnolia/Magnolia grandiflora L. Southern fruit-producing woody plants used by wildlife, 196-197.
Soltis, P., Soltis, D., & Edwards, C. (2005). Magnoliids. Web.