welwitschia

welwitschia

1. plants having small unisexual flowers and fleshy or winged fruit: in some classifications includes the genera Ephedra and Welwitschia as well as Gnetum.

一植物科花小单性果实肉质；在一些分类中包括麻黄属植物和千岁兰属以及买麻藤属。

2. There are three very different orders, each with only one genus: Gnetales (Gnetum), Ephedrales (Ephedra or joint-firs), and Welwitschiales (Welwitschia).

买麻藤分为三目，三目之间的差别极大，每目只含有一个属：买麻藤目（买麻藤属），麻黄目（麻黄属），百岁兰目（百岁兰属）。

3. Welwitschia mirabilis

百岁叶

4. Most gymnosperms retain archegonia except for the most advanced genera Gnetum and Welwitschia.

除了买麻藤属和百岁兰属以外大多数裸子植物还保留有颈卵器。