An order of flowering plants consisting of six families, the best known of which are Magnoliaceae (220 species) and Annonaceae (2200 species). The others contain some botanically interesting and peculiar plants (305 species), but none besides Myristicaceae (300 species) are commonly encountered. Previously, many authors have considered these families as among the most primitive of the flowering plants, but in all cases the plants exhibit some highly derived traits. Although their fruits are often cited as the most primitive in the flowering plants, their carpels are not fused but the edges are sealed, unlike those of Nymphaeaceae and Chloranthaceae, which are not sealed at maturity. Their “primitiveness” has been overemphasized; studies of sequences of deoxyribonucleic acid (DNA) demonstrate that Magnoliales are closely related to Laurales, Piperales, and Winterales, and then more distantly to the monocotyledons.
- 词性: noun
- 行业/领域: 科学
- 类别 普通科学
- Company: McGraw-Hill
创建者
- Francisb
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