Phytodinium

甲藻門Dinophyta

雙鞭藻綱Dinophyceae

植甲藻目 Phytodiniales

植甲藻科 Phytodiniaceae

植甲藻屬Phytodinium

描述：Cells free-living, symmetrical, spherical or ellipsoidal. Chloroplasts yellow, parietal, disc-shaped or stellate, eyespot absent. Cell wall very thin. The coccoid cell elongates before cell division and a transverse wall is formed at right angles to the long axis. The cell contents do not contract prior to cell division but the daughter cells are released as autospores when the parent cell wall disappears. Stigma, cingulum and sulcus not observed. Zoospores unknown.