Isothecium myosuroides
Isothecium stoloniferum
isothecium moss, slender mouse-tail moss, tree moss, variable moss
with stipe short to absent, secondary stems 2–4 cm, not julaceous when dry, irregularly branched, sometimes close, branches arching downward, branches of secondary system sharp-tipped, flagelliform branches frequently present, 2–5 cm, attenuate, with narrower smaller leaves;
pseudoparaphyllia foliose, sometimes toothed, often blunt and broad.
with stipe short, secondary stems 2–9 cm, julaceous, often acutely pinnate, sometimes irregularly branched, branches curving downward, branches of secondary system blunt, flagelliform branches sometimes present, to 5 cm, with smaller, more distant leaves with alar cells weakly differentiated;
pseudoparaphyllia foliose, blunt or deltoid, blunt or toothed.
1–2 cm.
1–1.5 cm.
1–1.5 mm.
1.5–2 mm.
stem leaves broadly or narrowly triangular;
margins nearly entire;
apex sometimes attenuate; ecostate or costa present;
alar cells barely differentiated, region small, to 1/10 leaf length.
stem leaves broadly triangular;
margins nearly entire;
apex attenuate; ecostate or costa present;
alar cells differentiated, region small, to 1/10 leaf length.
leaves ovate to ovate-lanceolate;
margins toothed throughout, most strongly in apiculus;
apex attenuate;
costa to 2/3 leaf length;
alar cells usually shorter, except in shoot decurrent portion, region well defined, small, sometimes excavate, at marginal insertion.
leaves lanceolate, ovate-lanceolate, or ovate;
margins coarsely toothed throughout;
apex attenuate;
costa single, often ending in spine;
alar cells isodiametric, except at insertion where rectangular, region often excavate, confined to base near margin just distal to insertion.
Isothecium myosuroides
Isothecium stoloniferum
The eastern representation of Isothecium myosuroides is clearly the same as the European species, but the relationship of western North American material is unclear. K. Ryall et al. (2005) supported this conclusion with molecular data, but some California specimens identified as this species suggest that further analysis is necessary to clarify their identity. Isothecium myosuroides, although showing some variability, is far more uniform than I. stoloniferum, and the infrequency of sporophytes in the former suggests that cloned populations are frequent. The stems of I. myosuroides are creeping and radiculose.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Isothecium stoloniferum is an extremely variable species strongly related to the less variable I. myosuroides. Isothecium stoloniferum differs in its genetic composition (K. Ryall et al. 2005). There is a morphotype of I. stoloniferum that resembles I. alopecuroides, but the leaves are not cucullate and the apex is acute and strongly toothed. This morphotype appears to be most frequent on boulders or outcrops in and beside streams, often in well-drained but humid sites.
The predominant morphotype of Isothecium stoloniferum has pinnate, acute-branched plants, sometimes with a stipe emerging from the primary system or proliferating from the secondary system, and can appear dendroid, especially when humid. The shoots are not julaceous, and flagelliform branches are infrequent. This morphotype tends to produce short stolons adventitiously usually near the base of the stipe. Another morphotype mimics I. myosuroides and is often impossible to distinguish; it is commonly epiphytic and tends to produce flagelliform branches; some populations can be composed entirely of flagelliform branches. Although the alar cells are less pronounced in this morphotype, the long-acuminate, strongly toothed leaves are characteristic.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
BC
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
CalFlora
Flora NW
