Cycadine

Cycadine

Cycads forest is an ancient and relic cycads plant discovered for the first time in the dry hot valley of Jinsha River in southern Sichuan recently. It was first found in the west slope of guanuan river near Dukou city. Later, it was successively found in the adjacent Geliping mountain and some areas of Ningnan, Dechang, Yanyuan and Huaping counties in Yunnan Province. Its distribution area is about 300 hectares, with more than 100000 plants and relatively stable communities.

brief introduction

However, it is disturbed and destroyed by fire, grazing, woodcutting and other factors. Especially since the report of Cycas Panzhihua, plant excavation is very frequent. In recent years, although some protective measures have been taken, the damage has not been eliminated.

Characteristics of Cycas forest

The distribution area of Cycas Panzhihua is located in the middle part of Jinsha River, with steep terrain, deep valley, large mountain height and closed terrain. Affected by the climate effect of dry hot valley, it has mild winter climate, sufficient sunshine and rich heat, belonging to the climate type of semi-arid Valley in South Subtropical Zone. The annual average temperature is about 20 ℃, the lowest temperature is - 1-2 ℃, and the extreme maximum temperature is 40.7 ℃; the annual precipitation is about 760 mm, and the dry and wet season is obvious. The wet season is from June to October, accounting for 89% of the annual precipitation, and the dry season is from November to May; the annual average relative humidity is 61%, while the February to May is less than 50%; the frost free period is 294 days. The soils are mountain carbonatite red cinnamon soil and mountain yellow cinnamon soil developed from limestone and sand shale parent rock, showing slightly acidic to neutral (occasionally alkaline) reaction. Cycas Panzhihua grows in clumps. The arbors in the community are sparse and low, and the appearance of the community is sparse and shrubby. The species of Cycas Panzhihua vary slightly with different altitudes.

It is a brown stream like evergreen plant, 1-2.5 meters high. Its stem is usually single and covered with the base of persistent petiole. Leaves spirally arranged, clustered at the top of stem, pinnately divided, 70-120 cm long, with spreading short spines on both sides of upper petiole; pinnae 70-105 pairs, linear, straight or slightly curved, thick leathery, 12-23 cm long, 6-7 mm wide, upper midrib raised, lower, glabrous, apex acuminate, base cuneate, oblique, margin flat or slightly retrorse. Microsporophylls are dioecious; microsporophylls are solitary, apex often oblique, spindle cylindrical or elliptic cylindrical, usually slightly curved, stems curved, 4-6 cm long, densely covered with rust Brown villi; microsporophylls are cuneate, 3-6 cm long, apex broadly triangular, with protruding spines in the center, glabrous above, yellow or light yellowish brown, glossy below, mostly 2-5 (usually 3-4) aggregated The megasporophylls are numerous, clustered on the top of the stem, spherical or hemispherical, 14-18 cm long, densely covered with yellowish brown to rust Brown villi; the upper part is flat, broadly rhombic or rhombic ovate, 8-10 cm long, 4.5-6 cm wide, feathery, lobes 30-40, subulate, 1-4 cm long; the lower part is petiolate, with 1-5 cm on both sides of the middle and upper parts (usually 3-4) ovules; ovules nearly square, glabrous, golden yellow, reddish brown at the top, with a small cusp in the center. Seeds subglobose or slightly oblate, about 2.5 cm in diameter, aril orange red, with thin paper, separated and fragile outer layer, seeds obconic or obovate spheroid, seed coat bony, smooth.

Address: No.98, Hemenkou North Street, West District, Panzhihua City

Longitude: 101.588922

Latitude: 26.612507

Chinese PinYin : Su Tie Lin