Amblystegium radicale (P.Beauv.) Mitt.

Authority

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

Family

Amblystegiaceae

Scientific Name

Amblystegium radicale (P.Beauv.) Mitt.

Type

Type. North America s.n. (lectotype, G, designated by Hedenäs, 1997a).

Synonyms

Amblystegium saxatile Schimp., Hypnum hygrophilum Jur., Hypnum radicale P.Beauv., Campylium radicale (P.Beauv.) Grout, Leptodictyum radicale (P.Beauv.) Kanda, Amblystegium saxatile Schimp.

Description

Species Description - Plants small (outside the area sometimes larger); green or yellow green. Stem irregularly or irregularly pinnately branched in one plane; central strand present, slender; pseudoparaphyllia triangular or narrow-triangular; paraphyllia sometimes present, narrow-lanceolate to ovate-lanceolate; axillary hairs with l-3(-4)-celled upper part, this hyaline when young. Stem leaves 0.70.9 mm long (outside the area sometimes longer), erect-patent to spreading, straight or somewhat squarrose, cordate or triangular-ovate, narrowing gradually or ± abruptly to apex, constricted at insertion, plane or slightly concave, narrow- or sometimes broad-decurrent (25-)35-50% of way down to leaf below; acumen channeled or shallowly so, the apex acuminate; margin finely or very finely denticulate, near insertion entire; costa single, ending 45-60% of way up leaf, 25.0-31.5 µm wide at base; median laminal cells 23.5-65.0 × 6.0-10.5(-11.5) µm, slightly incrassate, eporose or indistinctly porose; alar cells rectangular or short-rectangular, inflated, the widest cells to (10.0-) 18.0-25.0 |nm wide; alar group indistinctly delimited, broadly ovate or transverse-triangular, extending from leaf margin ca. 65% of distance to leaf middle at insertion, sometimes forming a concavity. Branch leaves sometimes subcomplanate. Inner perichaetial leaves narrowing abruptly to acuminate apex, plicate. Exostome outside cross-striolate in lower part. [Sporophytes not known from neotropical material.]

Discussion

Amblystegium radicale has been recorded from Mexico and Ecuador (e.g., Churchill, 1994; Delgadillo et al., 1995). I have not seen any correctly identified material from Ecuador. Among the Amblystegium species, A. radicale is recognized by its frequently cordate leaves with a ± channeled acumen, a costa ending somewhere in midleaf, and leaves that are decurrent (25-)35-50% of the way down to the leaf below. The plant often has a "Campylium-like" habit, that is, somewhat squarrose leaves in at least part of the shoots.

Distribution

Mexico (1920-2710 m a.s.l.). Widespread in temperate N America and Eurasia. Grows on the ground or on various kinds of organic material, in moist and periodically wet, nutrient-rich habitats such as swamps and swampy forests.

Mexico North America| Chiapas Mexico North America| Guanajuato Mexico North America|