Table 5.

Pollen morphology of Sinocarum species in scanning electron microscope (SEM).

Species	Type	Shape		Size(μm)	Polar axis/Equatorial axis(P/E)	Size index ($\sqrt{P\times E}$)	Exine ornamentation
		Equatorial view	Polar view				Equatorial area	Polar area
S. coloratum	super-rectangular	super-rectangular	trilobate circular	(27.20~32.90)30.36× (11.72~13.95)12.78	2.38 (2.16~2.59)	19.69 (18.51~20.00)	cerebro reticulate	cerebroid with a few perforations
S. cruciatum	super-rectangular	super-rectangular	trilobate circular	(26.07~32.15)28.84× (11.42~15.33)13.24	2.19 (1.80~2.56)	19.52 (17.25~20.92)	cerebro reticulate	cerebroid with a few perforations
S. filicinum	super-rectangular	super-rectangular	trilobate circular	(22.46~27.08)24.95× (11.12~13.57)12.56	1.99 (1.66~2.28)	17.69 (15.80~18.68)	cerebro reticulate	striate reticulate with a few perforations
S. schizopetalum	sub-rhomboidal	sub-rhomboidal	obtuse triangle	(18.27~20.81)19.61× (10.40~13.31)11.66	1.69 (1.56~1.92)	15.11 (14.15~16.62)	pitted reticulate	cerebroid
S. vaginatum	super-rectangular	super-rectangular	trilobate circular	(25.83~29.30)27.44× (10.92~14.62)13.58	2.03 (1.82~2.37)	19.29 (16.79~20.20)	cerebro reticulate	cerebroid with a few perforations