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Dicranaceae Schimp., Coroll. Bryol. Eur. 11. 1856.
曲尾藓科
Gao Chien, Dale H. Vitt and Si He
Plants small to robust, green to yellowish green or brownish green, in loose or dense, usually radiculose tufts. Stems often erect, simple or forked, rounded, rarely triangular, usually with central strand. Leaves in many rows, usually falcate-secund, mostly narrowly oblong-lanceolate, often broader at base, subulate in the upper half; margins plane or recurved, entire or serrulate to serrate; costa single, usually strong and long, ending near the leaf apex or excurrent, in cross section mostly with a row of median central guide cells; upper leaf cells variable in shape, smooth, rarely mammillose or papillose, lower laminal cells often elongate, alar cells often clearly differentiated. Dioicous or autoicous. Perichaetial leaves usually differentiated, sheathing at base. Setae mostly elongate, rarely very short, straight, flexuose or cygneous; capsules often exserted, erect, curved or inclined, ovoid, cylindric or pyriform, sometimes strumose at base; opercula generally differentiated, obliquely rostrate from a conic base; annuli present or absent, simple to complex; stomata present or absent; peristome teeth rarely lacking, usually present, well developed, 16, often reddish, dicranate to the middle, mostly lanceolate, deeply split into 2(–3) divisions, sometimes entire, vertically striate or smooth below, smooth or papillose above. Calyptrae cucullate, entire, smooth or sometimes fringed at base.
The Dicranaceae are a large family showing great variability and intermediate relationships with closely related families. It is difficult to characterize the family in any definitive way. In general, most members of this family have erect plants, falcate-secund, long, narrow, tapered leaves with a well developed, single, percurrent to excurrent costa, partially to well differentiated alar cells, elongate setae, exserted capsules, and flat, divided, vertically striate peristome teeth.
Most genera of the family are distributed in the temperate regions of the world except that a few genera, such as Campylopodiella, Campylopodium, Dicranoloma, Leucoloma, and Microcampylopus, are mainly found in tropical areas. Brotherus (1924) recognized six subfamilies, including 48 genera in the Dicranaceae worldwide. In China there are 32 genera that can be placed into Brotherus’s six subfamilies, although they are weakly delimited. The subfamilies, Paraleucobryoideae and Campylopodioideae, have recently been combined (Allen 1994). Several recent studies have also removed Bruchia and Trematodon from the traditional sense of the Dicranaceae (Buck 1979; Allen 1994). However, Rushing (1986) retained Bruchia and Trematodon in the Dicranaceae, awaiting a thorough evaluation of the family. Although there is no intention to treat or recognize the subfamilial divisions in this flora, the Chinese genera of the Dicranaceae may be grouped into six subfamilies (senus Brotherus 1924). Their systematic arrangements are:
Anisothecioideae: Anisothecium (=Dicranella), Aongstroemia, Aongstroemiopsis, Dicranella, and Microdus.
Campylopodoideae: Atractylocarpus, Campylopodiella, Campylopodium, Campylopus, Dicranodontium, and Microcampylopus.
Dicranoideae: Arctoa, Cynodontium, Dichodontium, Dicranoloma, Dicranoweisia, Dicranum, Holomitrium, Kiaeria, Leucoloma, Oncophorus, Oreas, Oreoweisia, Orthodicranum, Pseudochorisodontium, and Symblepharis.
Paraleucobryoideae: Brothera and Paraleucobryum.
Rhabdoweisioideae: Amphidium and Rhabdoweisia.
Trematodontoideae: Bruchia, Trematodon, and Wilsoniella.
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| 1 |
Costa in transverse section lacking guide cells, with a median layer of connected or disconnected small green cells or stereid cells |
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(2) |
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Costa in transverse section nearly always with large guide cells, without a median layer of green cells or stereid cells |
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(4) |
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| 2 (1) |
Alar cells clearly inflated; costal green cells in a median band, enclosed dorsally and ventrally by larger, thick-walled, hyaline cells or sometimes interspersed among the dorsal hyaline cells; annuli not developed |
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27 Paraleucobryum |
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Alar cells not much differentiated; costal green cells in a group of disconnected median stereids, enclosed dorsally and ventrally by large, thin-walled, hyaline cells; annuli well developed |
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(3) |
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| 3 (2) |
Costa generally narrower, less than 1/3 the leaf base width, with a few ventral stereids in the middle of costa; peristome teeth divided; plants usually green or yellowish brown when dry; brood bodies absent; leaf apex serrulate |
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8 Campylopodiella |
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Costa generally broader, more than 1/2 the leaf base width, without ventral stereids in the middle of costa; peristome teeth undivided; plants usually grayish green when dry; brood bodies common; leaf apex smooth |
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6 Brothera |
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| 4 (1) |
Neck of capsules well developed, broad or very long |
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(5) |
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Neck of capsules none, rarely very short and narrower |
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(7) |
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| 5 (4) |
Neck of capsules very long and narrow, at least as long as the urn |
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31 Trematodon |
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Neck of capsules short and generally broad, rarely as much as 1/2 the total length of the urn |
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(6) |
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| 6 (5) |
Opercula and peristome teeth none; setae very short; leaves sheathing at base, gradually narrowed to a short or long subula |
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7 Bruchia |
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Opercula and peristome teeth well developed; setae elongate; leaves not sheathing at base, gradually acuminate with obtuse apices |
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32 Wilsoniella |
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| 7 (4) |
Alar cells not or not noticeably differentiated |
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(8) |
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Alar cells clearly differentiated in a group, usually inflated |
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(22) |
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| 8 (7) |
Upper laminal cells mammillose or papillose |
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(9) |
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All laminal cells smooth |
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(12) |
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| 9 (8) |
Peristome teeth absent; capsules 8-ribbed when dry; laminal cells pluripapillose |
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1 Amphidium |
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Peristome teeth well developed; capsules smooth or furrowed when dry; laminal cells mammillose or conically to coarsely papillose |
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(10) |
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| 10 (9) |
Capsules furrowed when dry; leaves narrowly lanceolate, mostly acute at the apex, keeled; laminal cells often coarsely papillose |
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11 Cynodontium |
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Capsules smooth when dry; leaves broadly lanceolate or oblong-ligulate, broadly acute to rounded at the apex, subtubulose; laminal cells mammillose or conically papillose |
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(11) |
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| 11 (10) |
Peristome teeth forked, papillose |
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12 Dichodontium |
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Peristome teeth not forked, smooth |
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25 Oreoweisia |
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| 12 (8) |
Peristome teeth absent; stems julaceous; leaves broad, oval to oblong-ovate, rounded-obtuse or broadly acute at the apex |
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(13) |
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Peristome teeth present; stems not julaceous; leaves narrow, lanceolate, gradually narrowed to a sharp acute apex or abruptly narrowed from a strongly sheathing base to a subulate apex |
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(14) |
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| 13 (12) |
Dioicous; leaves oval, broadly acute, sharply bent to one side at the tips; costa percurrent; apical laminal cells irregular hexagonal or rhombic |
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2 Aongstroemia |
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Autoicous; leaves oblong-ovate, rounded-obtuse, straight at the apex; costa excurrent; apical laminal cells oblong-rectangular to rhomboidal |
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3 Aongstroemiopsis |
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| 14 (12) |
Capsules deeply 8-ribbed when dry; leaves oblong-lanceolate, slightly narrowed upward, sharply acute at the apex |
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29 Rhabdoweisia |
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Capsules smooth or irregularly furrowed when dry, not ribbed; leaves narrowly to linear-lanceolate, abruptly narrowed from a strongly sheathing or nonsheathing base, subulate at the apex |
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(15) |
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| 15 (14) |
Setae curved or cygneous when moist |
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(16) |
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Setae straight or sometimes flexuose when moist |
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(18) |
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| 16 (15) |
Autoicous; peristome teeth entire or slightly perforate, vertically striate throughout; leaf margins bistratose |
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24 Oreas |
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Dioicous; peristome teeth divided to the middle, vertically striate only at the base; leaf margins unistratose |
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(17) |
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| 17 (16) |
Capsules with stomata in the neck; spores finely papillose |
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9 Campylopodium |
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Capsules without stomata in the neck; spores warty |
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21 Microcampylopus |
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| 18 (15) |
Leaves strongly crispate when dry; upper laminal cells short, subquadrate to short-rectangular |
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(19) |
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Leaves not crispate or contorted when dry; upper laminal cells elongate, narrowly to oblong-rectangular |
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(20) |
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| 19 (18) |
Capsules curved, distinctly strumose |
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23 Oncophorus |
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Capsules erect, not strumose |
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30 Symblepharis |
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| 20 (18) |
Autoicous; calyptrae very large, longer than capsules; peristome teeth divided to the base |
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5 Atractylocarpus |
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Dioicous; calyptrae shorter than capsules; peristome teeth irregularly divided only to the middle |
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(21) |
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| 21 (20) |
Capsules globose, erect, symmetric; peristome teeth short, simple or irregularly split only at the tips |
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22 Microdus |
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Capsules subglobose to oblong-cylindric, asymmetric; peristome teeth elongated, clearly divided about halfway down or to the base |
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13 Dicranella |
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| 22 (7) |
Costa very broad, more than 1/3 the leaf base width |
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(23) |
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Costa narrow, less than 1/3 the leaf base width |
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(24) |
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| 23 (22) |
Capsules usually deeply furrowed when dry; annuli compound; calyptrae often fringed at the base; peristome teeth divided only to the middle; leaves not conspicuously setaceous |
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10 Campylopus |
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Capsules smooth when dry; annuli none; calyptrae often entire at the base; peristome teeth divided nearly to the base; leaves conspicuously long-setaceous |
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14 Dicranodontium |
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| 24 (22) |
Margins distinctly bordered by linear cells, usually hyaline near the leaf base; inner laminal cells differentiated |
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(25) |
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Margins not clearly bordered; inner laminal cells usually not differentiated from marginal cells |
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(26) |
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| 25 (24) |
Laminal cells coarsely compound-papillose |
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20 Leucoloma |
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Laminal cells smooth |
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15 Dicranoloma |
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| 26 (24) |
Upper laminal cells rounded or isodiametric, strongly incrassate; perichaetial leaves with markedly elongated, convolute sheaths enfolding the setae and extending 1/3 - 2/3 the seta length |
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18 Holomitrium |
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Upper laminal cells rectangular or elongate, moderately thick-walled; perichaetial leaves with short sheaths enfolding the setae only at the base |
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(27) |
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| 27 (26) |
Leaves crispate when dry |
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(28) |
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Leaves falcate-secund, not crispate when dry |
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(29) |
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| 28 (27) |
Peristome teeth undivided or only slightly divided at the tips, without vertical striate, smooth or papillose throughout |
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16 Dicranoweisia |
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Peristome teeth divided in the upper half or lower, with vertical striate nearly throughout |
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26 Orthodicranum |
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| 29 (27) |
Autoicous; costa in cross section lacking stereid band or with only a few poorly developed stereids; peristome teeth undivided or variously divided to the middle or less |
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(30) |
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Dioicous; costa in cross section with 2 stereid bands; peristome teeth divided in the upper 1/2 -2/3, sometimes the teeth poorly developed or lacking |
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(31) |
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| 30 (29) |
Setae 3-6 mm long, stout; capsules erect, obovoid, nearly symmetric, contracted below the mouth, tapered to the base when dry; peristome teeth irregularly divided in the upper half or less |
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4 Arctoa |
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Setae 7-16 mm long, slender; capsules suberect to inclined, oblong-cylindric, curved, sometimes strumose, not contracted below the mouth or tapered to the base when dry; peristome teeth clearly bifid halfway down |
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19 Kiaeria |
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| 31 (29) |
Peristome teeth absent; capsules erect; plants often yellowish green |
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28 Pseudochorisodontium |
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Peristome teeth well developed; capsules curved, suberect, horizontal or inclined; plants often bright green or brownish green |
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17 Dicranum |
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List of lower taxa
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