Origin and Habitat: Cycas panzhihuaensis is endemic to the Jinsha Jiang river valley in the South West Sichuan and North Yunnan (China). As with all mainland Asian cycads, human population pressure has had considerable impact, and present distributions may represent a small fraction of the distribution of only a century ago.
Altitude range: 3,610-6,562 ft (1,100-2,000 m) above sea level.
Habitat and ecology: This species grows in grassy places and thickets with sparse trees in on moderately to steeply sloping sites on limestone and sand shale. The climate is characterised by warm humid summers and cold frosty winters. Red List of Threatened Species this species was originally listed as Near Threatened in is now listed as Vulnerable because though found in six locations, populations there are continuing to decline due to exploitation of the plants and habitat clearance.
Description: The panzhihua tree (Cycas panzhihuaensis) is an erect, arborescent and usually unbranched cycad species which when mature mimicry the look of a short palm trees with a stout trunk about 2 m tall. This species can be easily tell apart from Cycas revoluta for its softer, looser habit and fairly stiff, dark green to blue-green leathery fronds that resemble those of a fern. Newly emerging fronds are soft green and flexible and radiate from a central point at the top of the woody trunk-like stem, this species flushes new growth more than once a year. Cycas panzhihuaensis may be one of the oldest living Cycad, surviving unchanged from the Mesozoic (100-190 million years ago).
Similar species:Cycas panzhihuaensis is similar to Cycas pectinata Buchanan-Hamilton but can be distinguished by the short stout unbranched trunk that is covered with a thick fur reddish brown wooly fur (tomentum), the slender, hard cataphylls, the narrow, dull to semiglossy bluish leaflets and the smaller orange-red seeds (up to 3.5 cm long).
Derivation of specific name: The specific epithet refers to the city of Panzhihua (alternatively spelled Panzihua) in Sichuan Province of China with the Latin termination 'ensis' meaning "place of origin" in reference to where this plant was first discovered.
Roots: All cycads have special upwardly growing multi-branched (coralloid) roots where nitrogen is fixed in symbiosis with Nostoc and Anabena algae.
Stem: Trunk cylindric, simple, to 2(-3) m tall, 25(-30) cm in diameter, apex densely tomentose. Bark brown to dark grey, scaly.
Leaves: 30-60(-80) in a crown, 1-pinnate, 0.7-1.3 m long, 18-25 cm wide. Petiole subrhombic in cross section, 7-20 cm long, with 5-13 spines along each side of apical part, base densely brown tomentose. Leaf blade oblong, flat to irregularly and slightly "V"-shaped in cross section, brown tomentose when young. Leaflets in 70-120(140) pairs, longitudinally inserted at 50-60° to rachis, straight to slightly falcate, 12-20 cm long, 6-7 mm wide, leathery, glabrous, midvein never sulcate adaxially, base decurrent, margin flat or slightly recurved, apex acuminate, pungent.
Cataphylls: The cataphylls (Modified leaf, much reduced and thickened, serving to protect the apical meristem in cycads produced in flushes preceding the emergence of cones or leaves.) are triangular-lanceolate, 6-9 long, 2-2.5 cm wide, densely brown tomentose.
Male cones: Fusiform- or ovoid-cylindric, 25-45 cm long, 8-12 cm across. microsporophylls narrowly cuneate, 4-6 long, 1.8-2 cm wide, apex broadly rounded, shortly cuspidate.
Female spike: When female inflorescences are present, the genus Cycas can easily be recognized by the loose structure of the inflorescence, as in all the other cycads genera the female inflorescences are compact cones. Instead Cycas panzhihuaensis carry ovules and seeds on more than 30 tightly grouped, leaf-like megasporophylls, 15-20 cm long, densely brown tomentose. Each on a stalk 8-12 cm long; sterile blade rhombic or rhombic-ovate, 8-10 long, 4-6 cm wide, margin glabrescent and pectinate, with 23-41 subulate lobes 1-3 cm, terminal lobe subulate, longer than lateral lobes; ovules 2 or 3 on each side of distal part of stalk, glabrous.
Seeds: 2-4, bright orange-red when mature, globose or obovoid-globose, slightly compressed, 2.5-3.5 long, 2.2-3 cm wide, apex shortly mucronate; sclerotesta smooth, shortly mucronate; fibrous layer absent; sclerotesta smooth. Spongy endocarp absent.
Phenology: Pollination Apr-May, seed maturity Sep-Oct.
Chromosomes number: 2 n=22
Note: For some reason Cycas panzhihuaensis is listed on the Plant List as a synonym of Cycas siamensis, a deciduous, slow and hard to grow species that was originally collected in Thailand and is also found in Cambodia, Laos, Myanmar, and Vietnam. This synonymy is contrary to how it is listed in Loran Whitelock's Cycad book and on the World List of Cycads.
Cultivation and Propagation: Cycas panzhihuaensis is easy to grow, tolerating dry periods, and frosts. It looks similar to the common sago palm (Cycas revoluta) but has much bluer leaves and is hardier. It prefers bright light exposure but best with some protection from afternoon heat.
Soil: This species needs a well drained spot, with deep soil, but will still thrive in less than ideal conditions, and is very tolerant of drought and alkaline soil.
Fertilization: Because of its growth habit, fertilize only when terminal bud begins to swell, indicating the start of the annual growth cycle.
Growth rate: This cycas is not so slow-growing as many other species, with heavy feeding is can be very fast growing with up to 3 flushes per year and growing a trunk up to 60 cm tall within 5 years from seed. In cold winter areas expect a once annual leaf flush in early to mid-spring.
Watering: Irrigate occasionally. Best were soil drainage is decent to avoid overly wet feet in winter rainfall climate.
Maintenance: Minimal; removal of offsets if desired, removal of spent fronds
Propagation: Seed or offshoots (or "pups"). The advantage of the "pups" is that you will know its sex, for seedlings you will have to wait several years until the plant flowers to find out. After fertile seeds are collected, they usually need several months of storage before the inner embryo is ready to germinate. Therefore, it is best to clean the seeds of external fruit and set them aside before attempting to propagate the seeds.
Hardiness: Cycas panzhihuaensis is a fairy hardy plant for a cycad and evergreen in climates with winter temperatures above 19°F (-7°C) and hardy but deciduous where temperatures drop below this and hardy to 61°F (16°C) and plantable in USDA Zone 7. ( some winter mulch and a site along a warm south facing wall to prevent deep soil freeze will definitely increase your chances of survival with growing this plant in cool climates ). Winter damaged plants may not sprout new foliage until late spring, so don't be quick to give up and remove your C. panzhihuaensis. They thrive in the mildest parts of the British Isles. C. panzhihuaensis enjoys hot humid summers and flourishes in the southeastern U.S.
Use: Landscape as cultivated perennial in warm, coastal areas; House-plant or interior-scape, as container plant in cool areas, as well very well suited to bonsai culture.
Warning: Best kept away from paths, since the leaves are quite stiff. The plants contain alkaloids of carcinogens and also an amino-acid that causes chronic nervous disorders. Regular consumption of the plant leads to severe health problems and death. Poisonous Parts: Fleshy seeds, leaves, unprocessed flour from stem pith. Symptoms: Vomiting, diarrhea, headache, dizziness, seizures.
"Cycas panzhihuaensis" Text available under a CC-BY-SA Creative Commons Attribution License. www.llifle.com 14 Nov. 2005. 07 Mar 2021. </Encyclopedia/PALMS_AND_CYCADS/Family/Cycadaceae/31950/Cycas_panzhihuaensis>