Drepanocladus aduncus (Hedw.) Warnst.

  • Authority

    Hedenäs, Lars. 2003. Amblystegiaceae. Fl. Neotrop. Monogr. 89: 1--107. (Published by NYBG Press)

  • Family

    Campyliaceae

  • Scientific Name

    Drepanocladus aduncus (Hedw.) Warnst.

  • Type

    Type. Germany. Sachsen: Chemnitz s.n. (G, lectotype, designated by Isoviita & Ochyra, 1990).

  • Synonyms

    Hypnum polycarpon Blandow ex Voit, Amblystegium kneiffii Schimp., Hypnum aduncum var. kneiffii (Schimp.) Schimp., Hypnum aduncum var. pseudofluitans Sanio, Drepanocladus simplicissimus Warnst., Brachythecium integrifolium Thér., Hygrohypnum arsenei H.A.Crum, Hypnum aduncum Hedw., Drepanocladus kneiffii (Schimp.) Warnst., Drepanocladus aquaticus (Sanio) Warnst., Drepanocladus aduncus var. pseudofluitans (Sanio) Glow., Hypnum simplicissimum Warnst.

  • Description

    Species Description - Plants medium-sized to large; green, yellow green, or brownish green. Stem pinnately or irregularly pinnately branched; pseudoparaphyllia broad; axillary hairs with l-2(-3)-celled upper part, this hyaline when young. Stem leaves straight or usually ± falcate-secund (gradually curved), ovate-lanceolate or ovate or triangular-ovate or rounded-triangular or broadly ovate, narrowing gradually to apex, not plicate, concave; acumen in straight-leafed plants plane or at most weakly furrowed; apex (obtuse or) acute or short- to long-acuminate; margin entire or occasionally finely denticulate; costa single, ending in midleaf or above; median laminal cells (10.0-)20.0-197.5(-262.5) × (4.0-)4.5-11.0(-12.5) µm, unistratose, thin-walled and eporose to incrassate and porose, ratio "median leaf laminal cell length (µm)/leaf length (mm)" 17.9-35.5 (rarely to 38.2); alar cells inflated, hyaline; alar groups transverse-triangular, reaching or nearly reaching costa. Dioicous. Inner perichaetial leaves narrowing abruptly to acuminate apex. Exostome outside cross-striolate in lower part. [Sporophytes not known from neotropical material.]

  • Discussion

    Note. The original material of Drepanocladus hygrohypnoides Herzog consists of a mixture of D. aduncus and a little D. polygamus.

    Drepanocladus aduncus has been reported from Mexico, Guatemala, the Dominican Republic, Peru, and Bolivia (Buck, 1998; Delgadillo et al., 1995; Hegewald & Hegewald, 1985; Sharp et al., 1994), and here Ecuador and Colombia are added to its distribution area. Among wetland pleurocarps with falcate-secund to completely ± straight leaves, D. aduncus is recognized by its somewhat lax or unordered appearance, with its leaves rarely as "well ordered" as in, e.g., Warnstorfla species; its total lack of red colors; its transverse-triangular alar groups that usually reach (sometimes almost reach) the costa; and by the total lack of rhizoid initials in the leaf lamina or on the costa. The variable habit of Drepanocladus aduncus has resulted in the recognition of several taxa. However, the quantitative characters that were employed for separating these taxa are size-dependent, and the different expressions are most likely environmentally induced (Hedenäs, 1996). The species most likely to be confused with D. aduncus is D. polygamus, and the differences between these two are discussed under the latter. Drepanocladus aduncus is also frequently confused with Warnstorfla species, especially with W. exannulata. However, Warnstorfla species frequently get red colors when growing in exposed habitats, whereas D. aduncus never gets red; Warnstorfla shoots are radially branched (in more sparsely branched specimens this may be difficult to see) but branching is distichous in Drepanocladus; and the leaf margins in Warnstorfla are usually at least partly distinctly denticulate (especially just above the alar groups and/or near the leaf apex), whereas they are entire or almost so in D. aduncus. When several leaves are checked, rhizoid initials are almost invariably found near the apex of at least some leaves of most Warnstorfla species (only very rarely in W. trichophylla), whereas leaf-borne initials are never found in Drepanocladus. Finally the very different ontogeny of the alar cells in these two genera is a safe separating character for the very few (sterile) specimens that are impossible to identify by means of the above characters. When successively older leaves are studied, starting with those having ± undifferentiated laminal cells, a stage with a square group of undifferentiated chlorophyll-rich cells is found in Drepanocladus species, whereas this is lacking in Warnstorfla. A more detailed account of the differences in alar cell ontogeny is found in Hedenäs (1987b). For the differences between D. aduncus and Leptodictyum riparium, see the notes after the latter.

    Illustrations: Crum & Anderson (1981: pp. 962, 964 [excl. "F"], Hedenäs (1993b: pp. 60, 61 [as D. sp.]), Nyholm (1965: pp. 436 [excl. "a"], 438).

    Distribution and Ecology: (Fig. 33) and ecology. Mexico (652835 m a.s.l.), Guatemala (1500-2255 m), Dominican Republic (1200-2500 m), Colombia (2000-3460 m), Ecuador (3450-3980 m), Peru (2400-4400 m), and Bolivia (2980-4620 m). Distribution ± continuous north and south of the neotropical region. Widespread in large parts of the world; in tropical and subtropical areas mainly on some higher mountains, in N America, Eurasia, Africa, Australia, New Zealand and Kerguelen. Found in relatively mineral-rich and ± nutrient-rich wetland habitats; in fens and swamps; on moist soil and rocks; on shores, in pools and slow-flowing streams; rarely in warm water at margins of hot springs. A somewhat weedy species that often grows in ponds, in ditches along roads, and in other anthropogenic habitats.

  • Distribution

    Mexico North America| Baja California Mexico North America| Chiapas Mexico North America| Guanajuato Mexico North America| Hidalgo Mexico North America| México Mexico North America| Michoacán Mexico North America| Nayarit Mexico North America| Oaxaca Mexico North America| Puebla Mexico North America| Veracruz Mexico North America| Baja Verapaz Guatemala Central America| Huehuetenango Guatemala Central America| Quiché Guatemala Central America| Sacatepéquez Guatemala Central America| Dominican Republic South America| La Vega Dominican Republic South America| Peravia Dominican Republic South America| San Juan Dominican Republic South America| Colombia South America| Cundinamarca Colombia South America| Meta Colombia South America| Nariño Colombia South America| Ecuador South America| Azuay Ecuador South America| Cotopaxi Ecuador South America| Napo Ecuador South America| Pichincha Ecuador South America| Peru South America| Cusco Peru South America| Junín Peru South America| Bolivia South America| Cochabamba Bolivia South America| La Paz Bolivia South America| Oruro Bolivia South America| Potosí Bolivia South America| Tarija Bolivia South America|