作 者 ：Geng Bao-Yin
期 刊 ：植物分类学报 1992年 3期
Keywords:Early Devonian, Vascular plants,
Abstract:
An Early Devonian flora from the Pingyiqu Formation of northern Sichuan is
described. It contains 13 species in 9 genera. They are Eogaspesiea gracilis, Uskiella sp.,
Zosterophyllum myretonianum, Z.yunnanicum, Z.sichuanense sp.nov., Oricilla unilateralis
sp.nov., Hicklingia cf.edwardii, Psilophyton sp., Drepanophycus spinaetormis, D.spinosus,
D.sp., Leclercqia complexa, and Sciadocillus cuneifidus gen.et sp.nov. The geologic range of
the flora is inferred to be Siegenian (probably Upper Gedinnian-Siegenian).
Sciadocillus gen.nov. (Marchantiales?)
Diagnosis: Thalli flattened, composed of a central disc-like structure and radiating
wedge-shaped unbranched lobes. Sporangium-like reproductive organs round to elliptic, at-
tached to the upper surface and along the edges of the lobes. Spores trilete.
Type species: Sciadocillus cuneifidus
Sciadocillus cuneifidus sp.nov.
Thallus, 4.2mm in diameter, consists of a central disc-like structure, about 1.0mm in di-
ameter, bearing 14 unbranched lobes. Lobes wedge-shaped, 1.5-1.75mm long , 0.75-
0.83mm wide at the apex and 0.25mm at the base. Sporangium-like reproductive organs
round to elliptic, 0.45-0.50mm long and about 0.4mm wide, without stalks. Spores,
spheroidal to subspheroidal, 20-40μm in diameter, trilete, exine smooth, sometimes folded.
Holotype: Plate 7:53, 54 (counterpart).
Locality: Approximately 800m, in northwest Yanmenba Village, Jiangyou, Sichuan.
Horizon: Lower part of Pingyipu Formation (Upper Gedinnian-Siegenian).
Zosterophyllum Penhallow (1892) (Zosterophyllaceae)
Zosterophyllum sichuanense sp.nov.
Plant with smooth axes at least 57mm long, 1.6-2.0mm wide, branching unknown.
Fertile axes terminate in lax spikes, about 6.5mm wide; spikes with spirally arranged
sporangia, three to four gyres. Sporangia borne on stalks, 2.7-3.9mm long and 0.54-
0.81mm wide; stalks obliquely inserted on axis, gentely cured upwards, in profile often
C-shaped with adaxial margins of sporangia; stalk contain vascular strand. Sporangia
Fan-shaped, often folded in half and margins facing axis, almost triangular in side view,
sometimes obovate in abaxial view; dehiscense not observed.
Holotype: Plate 2:11.
Paratype: Plate 2:10, 14.
Locality: approximately 800m, northwest Yanmenba Village, Jiangyou, Sichuan.
Horizon: Pingyipu Formation (Siegenian).
Oricilla Gensel (1982) (Zosterophyllaceae)
Oricilla unilateralis sp.nov.
Plants erect. Naked axes at least 76mm long, 1.6-3.2mm wide, branching
dichotomous with branching angles 30-60°in fertile regions. Sporangia borne laterally
in one row on branches, located above bifurcation, oriented to inside of axis. Stalks not
observed. Sporangia probably attached by an extremely short stalk to axis at right angle.
Sporangia reniform to ellitical, 2.8-4.0mm wide (X=3.3mm), 2.0-2.5mm high (X
=2.3mm) , composed of two equal valves, dehiscent along distal margin. Spores
subcircular, trilete, 48-58μm, in diameter, smooth, with dark area at juncture of trilete
rays. Surface covered with tapetal residue.
Holotype: Plate 4: 28.
Paratype: Plate 4: 30-32.
Locality: Approximately 800 m northwest Yanmenba Village, Jiangyou, Sichuan.
Horizon: Pingyipu Formation (Siegenian).