Etymology: From Taiwan, from where this species was (erroneously) thought to originate. Literature: Wang 1996. Illustrations: Carruthers 1893. Historical notes: C. taiwaniana was described in 1893 by English botanist and palaeontologist William Carruthers (1830-1922). The species was based on specimens he discovered in the herbarium of Henry F. Hance (a British consular officer in China from 1844 to 1886), which had since been acquired by the British Museum. These were collected by Robert Swinhoe, another British consular officer, who had also sent specimens to J.D. Hooker at Kew. The first of the latter was a single megasporophyll sent from the British Consulate at Amoy [Xiamen], where Swinhoe was the British representative, on 21 Aug 1867. This specimen was accompanied by a letter to Hooker in which Swinhoe wrote `Among the [silkworm] cocoons now sent you will find two specimens of an extraordinary leaf. I have worked at it in vain to make out its relations. It looks like a botanical caricature of a Pelican. The Chinese call it Hai-te-koe or sea-iron fowl (sea-iron is the name given to the coral submarine trees), and use it to flavour tea. They tell me it is found in fresh-water wells, but it is so rare here that I have not been able to ascertain how it grows, and whether the leaf constitutes the entire plant. ...'. Swinhoe later the same year acquired more complete material, and sent additional specimens to both Hance and Hooker. Carruthers in the protologue stated `No more definite information is contained on the label than that the specimens were collected on the island of Formosa by Mr. Swinhoe, and sent to Dr. Hance in the autumn of 1867, from whose herbarium, as I have said, came the specimen in the British Museum on which the species is founded.' This statement is based on the annotation on the sheet, stating `Cycas, L./ circinalis L./ Ex insula Formosa,/ autumn 1867 misit/ cl. Swinhoe.' This annotation is not in Swinhoe's hand, and may have been made by Hance. There is no indication from Swinhoe of exactly where the specimens were collected. Thiselton-Dyer (1902) addressed the problem of the origin of these specimens, and cited correspondence from British representatives in China to Kew. He stated that `Mr. G. Phillips, H.B.M. consul at Takow [?] and later Swatow [Shantou] took much trouble to find Swinhoe's plant. He eventually discovered it in 1883 "on the hills 60 miles from Swatow" and sent specimens to Kew.' Phillips also wrote to Kew stating that he had never seen the plant in Taiwan, and that it was much sought after as a garden plant on the mainland. Thiselton-Dyer also cited specimens collected in the Lofu-Shan by Ford as this species, but did not recognize a distinction between the mainland and Taiwanese plants. More recent Chinese accounts (Cheng, Fu & Cheng 1975, 1978) correctly apply the name C. taiwaniana to the mainland plants, but do not recognize the distinctive nature of the Taiwan plants (see C. taitungensis). Distinguishing features: Cycas taiwaniana is placed with the wider group of Chinese species (Section Stangerioides) by the soft microsporangiate cones, the loose, freely peeling sarcotesta lacking a fibrous layer and the verrucose sclerotesta. Within this group, it is distinguished by the more robust stature with distinct development of an aerial trunk and a large crown of leaves, and small seeds. Megasporophylls are larger but extremely variable in outline, as with many of the species in this section. Leaflets are moderately narrow but again highly variable, and distinctly twisted on the rachis. Distribution and habitat: Widespread but sporadic, in Guangdong and Guangxi Provinces, China. This species has long been cultivated in Guangdong and Fukien Provinces. Most collections, if not all, are from cultivated plants, and C. taiwaniana is now extremely rare in the wild. Reports of C. taiwaniana from Taiwan are the result of the misapplication of this name to the Taiwan cycad (C. taitungensis). Conservation status: Although originally widespread, this species has been severely depleted by collection from the wild and by habitat destruction over the centuries. Surviving populations are fragmentary and in remote sites and although probably reasonably secure by virtue of inaccessibility, must still be regarded as under substantial threat. This species was listed by the 1997 IUCN Red List of Threatened Plants as category V, but distribution is recorded in this listing as Hainan Island and Taiwan, which is clearly incorrect. IUCN (1994) Red List status DD, probably EN. Vernacular: taiwan sutie (China).
Description:
Stems arborescent or acaulescent, to 3.5 m tall, 15-30 cm diam. at narrowest point; 12-30 leaves in crown. Leaves deep green, highly glossy, 150-300 cm long, slightly keeled or flat (not keeled) in section (opposing leaflets inserted at 160-180° on rachis), with 140-300 leaflets, with orange or brown tomentum shedding as leaf expands; rachis consistently terminated by paired leaflets. Petiole 40-150 cm long (30-60% of total leaf), petiole glabrous, spinescent for 100% of length. Basal leaflets not gradually reducing to spines. Median leaflets simple, strongly discolorous, 180-440 mm long, 9-16 mm wide, inserted at 45-85° to rachis, decurrent for 5-6 mm, narrowed to 3-5 mm at base (to 25-30% of maximum width), 10-24 mm apart on rachis; median leaflets section flat; margins slightly recurved; apex aristate, spinescent; midrib raised above, flat below. Cataphylls narrowly triangular, pungent, pilose to densely floccose, 85-130 mm long, persistent. Pollen cones narrowly ovoid to fusiform, yellow, 30-45 cm long, 8-10 cm diam.; microsporophyll lamina soft, not dorsiventrally thickened, 20-30 mm long, 5-15 mm wide, apex level, apical spine absent. Megasporophylls 15-22 cm long, brown-tomentose; ovules 2-6, glabrous; lamina orbicular, 70-120 mm long, 55-70 mm wide, deeply pectinate, with 24-52 soft lateral spines 20-42 mm long, 1-2 mm wide, apical spine distinct or not distinct from lateral spines, 20-45 mm long, 7-30 mm wide at base. Seeds subglobose to ovoid, 28-36 mm long, 20-30 mm wide; sarcotesta yellow, not pruinose, 2 mm thick; fibrous layer absent; sclerotesta verrucose. Spongy endocarp absent.
|
