学名(拉丁名) | Aleuritopteris pygmaea |
中文名 | 矮粉背蕨 |
命名人 | Ching ex S. K. Wu |
中文科名 | 中国蕨科 |
拉丁属名 | Aleuritopteris |
类型 | species |
拉丁科名 | Sinopteridaceae |
中文属名 | 粉背蕨属 |
学名(拉丁名) | Aleuritopteris pygmaea |
命名人 | Ching (accepted name) |
拉丁属名 | Aleuritopteris |
类型 | species |
拉丁科名 | Pteridaceae |
学名(拉丁名) | Aleuritopteris pygmaea |
命名人 | Ching |
发表年份 | 1981(年) |
拉丁属名 | Aleuritopteris |
类型 | species |
拉丁科名 | Pteridaceae |
学名(拉丁名) | Aleuritopteris pygmaea |
中文名 | 矮粉背蕨 |
拉丁属名 | Aleuritopteris |
类型 | species |
拉丁科名 | Pteridaceae |
学名(拉丁名) | Aleuritopteris pygmaea |
中文名 | 矮粉背蕨 |
中文科名 | 中国蕨科 |
拉丁属名 | Aleuritopteris |
类型 | species |
拉丁科名 | Sinopteridaceae |
中文属名 | 粉背蕨属 |
学名(拉丁名) | Aleuritopteris pygmaea |
发表年份 | 1981(年) |
拉丁属名 | Aleuritopteris |
类型 | species |
拉丁科名 | Pteridaceae |
Rhizomes ascending, short; scales bicolorous, dark brown with light brown margins, lanceolate. Fronds clustered. Stipe reddish brown, 1-2 cm, densely covered with concolorous brown scales and fibrous, twisted hairs, these extending onto rachis and costae. Lamina ovate, 1.3-1.5 × ca. 1 cm, bipinnatifid, papery when dry, abaxially with snow-white farina and sparse hairs, adaxially glabrous. Pinnae 3 or 4 pairs, opposite, slightly oblique upward; basal pair of pinnae widely separated from adjacent one, ca. 0.6 cm, pinnatipartite; ultimate segments 3 or 4 pairs, obliquely spreading, basal basiscopic segment larger, entire; second pair of pinnae subequal to or slightly longer than basal one, base decurrent or not. Veins obscure. Sori sparse, discontinuous, consisting of 2 or 3 sporangia. False indusia continuous, narrow, margins entire.
Rock crevices in valleys; 3800-3900 m. Xizang.
Aleuritopteris pygmaea is the smallest species in the genus. It is distinguished from other species by its reddish brown stipe, which is densely covered with scales and twisted, long hairs.
We have not seen material of Aleuritopteris mengshanensis F. Z. Li (Acta Phytotax. Sin. 22: 153. 1984), described from Shandong. It appears to be most closely related to A. pygmaea but without the twisted hairs on the stipe.
2.矮粉背蕨(植物分类学报)图版39:6-8
Aleuritopteris pygmaea Ching ex S. K. Wu in Acta Phytotax. Sinica. 19 (1)61. 1981; Ching et al. in C. Y. Wu, Fl. Xizang. 1:80. 1983.
植株高2.5-3厘米。根状茎斜升,先端的鳞片密,披针形,亮深棕色,不透明,边缘淡棕色,全缘。叶簇生;柄长1-2厘米,纤细,红棕色,密被同样的鳞片和纤维状的卷曲长毛,向上分布到叶轴及羽轴;叶片卵圆形,长约1.3-1.5厘米,宽约1厘米,二回羽裂;羽片3-4对,对生,略斜向上,与叶轴合生,基部一对与其上羽片远分开,长约0.6厘米,羽裂达2/3-3/4;裂片3-4对,斜出,羽轴两侧的裂片几同形同大,基部下侧一片较大,全缘;第二对羽片和基部一对羽片等长或略长,基部略下延或不下延;侧生裂片2-3对,三角形,全缘;叶脉两面不显。叶干后为纸质,下面密被雪白色的粉末和疏被节状毛,上面光滑。孢子囊群稀疏,由2-3个孢子囊组成,彼此分开;囊群盖线形,绿色,由几不变质的叶边反卷而成,远离主脉,紧贴叶面,全缘。
特产西藏(拉萨、曲水),生河谷洪积扇石缝中,海拔3 800米。
本种是本属中最矮小的种类。叶柄红棕色,密被鳞片和卷曲的长毛,叶片不为五角形而为卵圆形,通常长过叶柄,易与同属其他种区别。