科達樹(學名:Cordaites)是一屬已滅絕的樹狀植物,與種子蕨類同樣由前裸子植物演化而來,為現今銀杏類與松柏類植物的祖先。[2]科達樹既生長在乾旱地區,也能生長在與佛羅里達州大沼澤地相似的濕地中,常在其樹根部位發現鹹水淡菜類和甲殼類的化石。它們的化石被發現於全球各地的上石炭紀地層中。[2]
科達樹的植株很大,可達30公尺。帶狀的葉於枝條上排列成緊密螺旋狀。葉上有獨特的平行脈。[2]其繁殖器官被稱為科達穗(Cordaianthus),為單性的,但不易分辨其雌雄。花粉為顆粒狀的弗氏粉屬(Florinites),直徑約50微米,尚未發現其花粉管。毬果位於枝條的末梢。[2]種子亦不少見,外型相當大,大小從二、三毫米至2釐米不等,呈扁心形,可分為高特果(Cordaicarpus)、心果(Cardiocarpus)和翅果(Samaropsis)三種。
- Cordaites daviessensis
- Cordaites hislopii [3]
- Cordaites kinneyensis
- Cordaites ludlowi
- Cordaites lungatus
- Cordaites minshallensis
- Cordaites olneyensis
- 帶科達 Cordaites principalis
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