Cycads: Cycas taitungensis

Origin and Habitat: Taiwan. This species is known only from the mountainous southern parts of Taitung (Taidong Xian) province of Taiwan. Populations are in the Lu-Yeh Valley near Yenping Hsiang and to the west of the Taitung Coastal Range in Tunghe Hsiang. (Extent of occurrence is 65 km², the species is known from two locations and there is continuing decline in mature individuals. At least 1,700 plants occur in the Taitung Hongyeh Village Cycas Nature Reserve.).
Altitude range: Cycas taitungensis occurs from 984-3,281 ft (300-1,000 m) above sea level.
Habitat and Ecology: This species occurs in mixed, sparse forests in exposed sites on rocky and steep slopes or in well-drained gravel mixed with other sun loving, drought tolerant plants. The habitat is subjected to periodic fires. Invasion by Aulacaspis scale has started to cause decline, mortality of > 50% is expected within at least one generation. Poaching of plants, propagules, seedlings and seeds from habitat plants also poses a threat to this species.

Description:Cycas taitungensis is a relict species from Taiwan. It is an elegant erect palm-like plant with a stout simple or branched trunk up to 5 m tall; the leaves forming a graceful crown at the summit. Cycas taitungensis is very similar to the common Cycas revoluta from which it differs only for the longest flatter fronds with long, large and flat leaflets. Furthermore, the female cones tend to be more tightly imbricate and cabbage-like. The seeds are darker than those of C. revoluta. Typical of all the family, the plants are dioecious.
Derivation of specific name: From the prefecture of Taitung, a mountainous region in south-eastern Taiwan, where this species is native, with the Latin termination -ensis, place of origin.
Trunk: Arborescent sometimes branched, 3-5(-6) m tall, 25-30(-45) cm in diameter, apex very tomentose; bark black, scaly.
Leaves: to 50 or more, 1-pinnate, deep green, semiglossy, (100-)130-180(-200) cm long, 20-30(-40) cm wide. Petiole (10-)15-25 (-30) cm (15-20% of total leaf), subtetragonal in cross section, glabrous with 7-14 spines along each side (spinescent for 50-90% of length). Leaf blade oblong, strongly "V"-shaped in cross section, recurved, densely orange-brown tomentose when young shedding as leaf expands; leaflets in 130-200 pairs, horizontally inserted at 55-65° above rachis, straight to subfalcate, not glaucous when mature, 14-20 cm × 5-8 mm, leathery, sparsely pubescent abaxially, base decurrent, margin flat or slightly recurved, midrib flat above, raised below, rachis usually terminated by a spine. Basal leaflets gradually reducing to spines, 30 mm long.
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, 4-7 × 1.7-2.5 cm, densely pale brown tomentose, apex pungent.
Pollen cones: ovoid-cylindric to fusiform, (35-)45-55 long, 8-10(-13) cm in diametres; microsporophylls narrowly obtriangular, 3.5-4.5 × 1.1-1.5 cm, apex cuspidate.
Megasporophylls: Like other Cycas species, the female plants do not bear cones; instead they carry ovules and seeds on large, bright orange-red, spadelike megasporophylls, which are 15-28 cm, pale brown tomentose, glabrescent; stalk 8-17 cm; sterile blade suborbicular or rhombic-orbicular, 7-14 × 6-11 cm, pectinate, with 29-39 lobes 2-4.5 cm; ovules 2(or 3) on each side of stalk, densely pale brown tomentose.
Seeds: 2-6, orange-red, narrowly obovoid or subellipsoid, 4-5 × 2.5-3.3 cm, often with remnant hairs; sarcotesta red, slightly pruinose, 1.5-3 mm thick; fibrous layer absent; sclerotesta with 2 or 3 irregular grooves on each side.
Phenology: Pollination Apr-Jun, seed maturity Sep-Oct.
Note: Plants now treated as Cycas taitungensis were formerly misidentified as Cycas taiwaniana, a species occurring in Guangdong, E Guangxi, SW Hunan, SE Yunnan, and possibly Vietnam. The former is distinguished by the narrower leaflets, with a shining upper surface and a somewhat hairy lower surface bearing a slightly elevated midvein of the same color and its seeds are narrowly obovate with peculiar horizontal wrinkles.

No items found.

Cultivation and Propagation: Cycas taitungensis is easy to grow, tolerating dry periods, and light frosts. It prefers bright light exposure but color bleaches when in full sun; best with some protection from afternoon heat. Needs a well drained spot, with deep soil, but will still thrive in less than ideal conditions, not tolerant of alkaline soils. Usually slow growing, however good conditions can speed it up considerably. Because of its growth habit, fertilize only when terminal bud begins to swell, indicating the start of the annual growth cycle.
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.
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.
Edibility: Processed flour, toxic if large quantities eaten.

"Cycas taitungensis" 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/30173/Cycas_taitungensis>