原始色素體生物

原始色素體生物 化石時期：
Indian paintbrush and wild huckleberry
科學分類
域： Eukaryota （未分级） Archaeplastida Adl et al. 2005
Subgroups
Red algae Glaucophytes Plantae (land plants and green algae)

原始色素體生物（Archaeplastida）是一種泛植物原生生物，是原生生物的主要群體，其中包括紅藻、綠藻、陸生植物及少量合稱為灰色藻的生物。除了植物以外，這個組的其他生物具有部份植物特性，但欠缺部份植物必須存在的特質的生物，例如：沒有植物必須的葉綠素的其他藻類。

The plastids (chloroplasts) of all of these organisms are surrounded by two membranes, suggesting they developed directly from endosymbiotic cyanobacteria. In all other groups, plastids are surrounded by three or four membranes, suggesting they were acquired secondarily from red or green algae.

The cells of the Archaeplastida typically lack centrioles and have mitochondria with flat cristae. There is usually a cell wall including cellulose, and food is stored in the form of starch. However, these characters are also shared with other eukaryotes. The main evidence the Archaeplastida form a monophyletic group comes from genetic studies, which indicate that their plastids probably had a single origin. This evidence is disputed.

The archaeplastidans fall into two main evolutionary lines. The red algae are pigmented with chlorophyll a and phycobiliproteins, like most cyanobacteria. The green algae and land plants – together known as Viridiplantae (Latin for "green plants") or Chloroplastida – are pigmented with chlorophylls a and b, but lack phycobiliproteins.

以下為原始色素體生物的組成部份：

• 植物綱
• 灰胞藻門（Glaucophyte）：The glaucophytes have typical cyanobacterial pigments, and are unusual in retaining a cell wall within their plastids (called cyanelles).
  • 灰胞藻綱(Glaucocystophyceae)
    • 灰胞藻
• 紅藻門(Rhodophyta)，如石花菜、紫菜。
  • 紅藻