Cycas collina
| Cycas collina | ||||||||||||
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| Scientific name | ||||||||||||
| Cycas collina | ||||||||||||
| KDHill , THNguyên & PKLôc |
Cycas collina is a species of cycads (Cycadophyta)nativeto Southeast Asia .
features
The trunks are 15 to 80 cm high and 8 to 13 cm in diameter. They are mostly underground or prostrate. The crown consists of two to five leaves . These are light to dark green, slightly shiny, 1.4 to 3.3 meters long, flat and not keeled. They have 110 to 180 leaflets. The orange felt is thrown off as it grows. The rachis ends with the pair of leaflets. The petiole is 70 to 190 cm long, glabrous and prickly for most of its length. The basal leaflets are 20 to 26 centimeters long. The middle leaflets are simple, 28 to 45 centimeters long and 17 to 23 mm wide. The feather tips are softly pointed, not prickly.
The cataphylls are narrow, triangular, soft, hairy and 4 to 8 cm long.
The microsporangiate cones are spindle-shaped, cream-colored, 20 to 25 cm long, 9 to 11 cm in diameter. The blade of the microsporophyll is soft and not thickened dorsiventrally. It is 12 to 14 mm long, 7.5 to 10 mm wide, with the sterile tip 3 to 6 mm long.
The blade of the megasporophylls is 10 to 14 cm long, hairy brown tomentose. They have two to four bald ovules . The seeds are egg-shaped, 25 to 27 mm long and 18 to 21 mm wide. The sarcotesta is yellow, one fiber layer is missing. The sclerotesta is slightly wrinkled, a layer of sponge is missing.
Distribution and locations
Cycas collina occurs only in the Son La province in northern Vietnam . It grows in the mountain regions over 500 m above sea level in evergreen or partially deciduous forests or bamboo thickets on the steep slopes of the mountains. The subsoil is red clay soil over sandstone or loamy soil over metasediments. The species is probably also found in neighboring areas in Laos .
supporting documents
- Ken D. Hill, Hiêp T. Nguyen, Phan K. Loc: The Genus "Cycas" (Cycadaceae) in Vietnam. In: The Botanical Review. Vol. 70, No. 2, April / June 2004, ISSN 0006-8101 , pp. 134-193, doi : 10.1663 / 0006-8101 (2004) 070 [0134: TGCCIV] 2.0.CO; 2 .
Web link
- Cycas collina inthe IUCN 2013 Red List of Threatened Species . 2. Posted by: Nguyen, HT, 2009. Retrieved April 28, 2014.