DICKSONIACEAE [FIRST DRAFT]
蚌壳蕨科 bang qiao jue ke
Zhang Xianchun (张宪春)[1];
Tree ferns with tall stout trunks or prostrate rhizomes, covered with a mass of long hairs. Frond large, 2-3-pinnate-pinnatifid; veins forked or pinnate, free, ending near the margin. Sori marginal or submarginal, terminal on veinlets. Sori single one vein ends, submarginal, protected by an abaxial (‘inner’) indusium and a hardly to strongly modified lobe of the lamina segment (‘outer indusium’), connate at the base, cup-like to box-like; sporangia gradate, annulus complete, oblique; paraphyses few or abundant. Spores trilete.
Dicksoniaceae is close to other tree ferns. Kramer (1990) included in the family the following genera, Dicksonia, Cibotium, Culcita, Calochlaena, and Thyrsopteris, mainly in tropical regions. Cibotium is the only genus present in the fern flora of China. All species are listed in CITES appendix II.
1. CIBOTIUM Kaulf., Berliner Jahrb. Pharm. Berlin. Jahrb. Pharm. Verbundenen Wiss. 21: 53. 1820.
金毛狗蕨属 jin mao gou jue shu
Very large terrestrial ferns; rhizome massive, creeping to erect, occasionally to several meters tall, solenostelic or sometimes dictyostelic, bearing roots and persistent petiole bases, densely covered with yellowish-brown, multi-cellular long hairs. Fronds close, forming a crown at the apex; stipe with 3 corrugated vascular bundles, 1 abaxial, 2 adaxial, with much incurved ends; aerophores (pneumatophores) forming a line on each side; adaxial face of petiole flattened; laminae 2-pinnate + pinnatifid to 3-pinnate + pinnatifid, monomorphic or dimorphic, firm, often glaucous beneath, glabrous when mature or persistently hairy on rachis, costa, costule and veins; rachis adaxially raised, hairy in the middle, in dried material often sulcate in the middle of the ridge which is flanked by 2 grooves; stomata paracytic; veins free, simple or forked to pinnate; sterile segments entire or crenate; fertile segments not differentiated. Sori single one vein ends, submarginal, protected by an abaxial (‘inner’) indusium and a modified lobe of the lamina segment (‘outer indusium’), connate at the base, box-like; paraphyses few, short, brown. Spores tetrahedral-globose-trilete, with extended angles and usually prominent equatorial flange. Chromosome number n = 68.
10-12 species. 3-4 in Asia, from north-eastern India, southern China, and the Ryukyus to Taiwan, the Philippines, Malaysia, Indonesia, New Guinea, and Pacific islands, 4-5 are endemic to Hawaii, 2 in Mexico. Plants usually in open areas in tropical hill and submontane forest at elevations of 500-2500 m, where they may form thickets, they may occur on banks and road cuts, some are fire resistant and will persist after land clearance.
Spores of all species are trilete. In Old World species, equatorial ridges or flanges are common; these are usually missing in American species. The spore surface is usually scabrate to granulate.
Key to species
1a. Pinnules on the basiscopic side of lower pinnae present; usually with 1 or 5 sori at the base of the lower pairs of pinnule-segments; spores with an equatorial flange. ……….. 1. C. barometz
1b. Pinnules on the basiscopic side of lower pinnae usually lacking; usually with 1 or 2 sori at the base of the lower pairs of pinnule-segments; spores without an equatorial flange. ……………………………………………………………………………. 2. C. cumingii
1. Cibotium barometz (L.) J. Sm. in Hooker, London J. Bot. 1: 437. 1842.
金毛狗蕨 Jin mao gou jue
Polypodium barometz L., Sp. Pl. 2: 1092. 1753; Dicksonia barometz Link; C. assamicum Hook.
Rhizome stout, prostrate, densely covered with shining brown long hairs. Fronds close; stipes thick, up to 1 m long or more, triangular in transverse section at base, densely bearing caducous adpressed hairs, stipe and rachis green, turning purplish beneath with age; with a continuous or broken row of linear aerophores on each side of stipe, base of stipe with a mass of long (1-1.5 cm) hairs, upper part of stipe and rachis covered with small, appressed flaccid hairs becoming glabrescent; laminae 2-pinnate-pinnatifid, 1.5-3 m long; medial pinnae 40-80 x 15-30 cm, lower pinnae shortened, deflexed; pinnae many, alternate, stalked, pinnules short stalked, usually of about equal length on either side of rachilla; pinnule-segments slight falcate, apiculate, margins crenulate to serrulate-serrate; veins free, fertile ones simple, sterile simple or forked; laminae subcoriaceous, upper surface deep green, lower surface glaucous, glabrous on both sides, except the hairy midrib; venation visible on both surface, free, lateral veins simple or forked. Sori 1-5 pairs on pinnule-segments; indusia bivalvate, outer indusia round, inner ones more or less oblong; outer valve of indusium usually large; paraphyses dark reddish brown. Spores pale yellowish, with equatorial flange.
In warm and humid environment, often in valley, forest edge and open place in forest, at elevation ranges from (50-) 200-600 (-1300-1600) m. Chongqing, Fujian, Guizhou, Guangxi, Gungdong, Hainan, Hunan, Jiangxi, Sichuan, Taiwan, Zhejiang, Yunnan, and Xizang [NE India, western Malay Peninsula, Indonesia (from Java to Sumatra), Myanmar, Thailand, Vietnam, and Japan].
It is rather common in southern subtropical regions and tropical regions, usually growing with Alsophila spinulosa, Diplopterygium chinense, Dicranopteris pedata etc., sometimes forms community, abundant. It is an acid soil indicator species in tropical and subtropical areas, mainly distribute in South and Southwest China, Guangxi, Guangdong and Guizhou are the main distribution areas, then are Yunnan and Sichuan. The most north distribution of this species in China reaches the Yangtze River in Chongqing.
The rhizome of this plant is very thick, woody, covered by long soft, golden yellow hairs, looks like a golden hair dog. Therefore, the plant is called “Jinmao Gouji” (Golden Hair Dog), or “Huanggoutou” (Yellow Dog’s Head) in China. It is a famous traditional Chinese herb medicine known as “Gouji” (Cibot Rhizome, Rhizoma Cibotii). Hairs of the rhizome and stipe are also used as a wound dressing and to staunch blood loss. It is listed in CITES appendix II, conservation and sustainable use should be attained.
2. Cibotium cumingii Kunze, Farrnkrauter 1: 64. 1841.
菲律宾金毛狗蕨 fei lv bing jin mao gou jue
C. barometz var. cumingii (Kunze) C. Chr.; C. taiwanense C.M. Kuo.
Very similar to C. barometz in general. The pinnules on the basiscopic side of lower pinnae usually lacking; the pinnules on the larger pinnae 12-15 cm x 12-16 mm; usually with 1 or 2 sori at the base of the lower pairs of pinnule-segments; spores without an equatorial flange.
In open forest or on road cuts and slopes in hilly and montane areas. Taiwan [Philippines]. In Taiwan, it is locally more common than C. barometz.
[1] Herbarium, Institute of Botany, Chinese Academy of Sciences, 20 Nanxincun, Xiangshan, Beijing 100093, People’s Republic of China.