BFNA Title: Ulota
Author:  D. H. Vitt.
Date: October 6, 2003
Edit Level: R Brum+
Version: 1

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden

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Ulota - Orthotrichaceae


8.  Ulota C. Mohr, Ann. Bot. 2: 540  1806 * [referring to curled leaves of some species]

Dale H. Vitt

Plants to 5.5 mm.  Stems erect or rarely creeping, ± branched.  Leaves contorted-crisped to slightly twisted and erect-curved when dry, erect-spreading to spreading-flexuose when moist, 1--1.4 mm, oblong- to linear-lanceolate, usually from an ovate base, acuminate, acute, or narrowly obtuse, base usually clasping stem; margins entire, plane or reflexed; costa ending near apex or rarely excurrent; distal cells 6--13 µm wide, hexagonal-rounded to elliptic, with very incrassate walls and conical papillae, sometimes smooth; interior basal cells radiating from insertion, rectangular-elongate to elliptic, often nodose, very thick-walled, usually orange, sharply grading to thin-walled, hyaline, quadrate marginal cells.  Brood bodies rarely present, if so, then only at tips of leaves.  Perichaetial leaves larger. Sexual condition autoicous or rarely dioicous.  Seta 1.5--10 mm. Capsule 0.6--3.2 mm, fusiform-cylindric, ovate-oblong or rarely obovate, lightly 8-plicate at mouth to moderately 8-ribbed entire length, fully exserted, mouth puckered or capsule ± constricted beneath mouth, gradually contracted to seta through long neck; stomates superficial; peristome double or single; exostome teeth 8, sometimes split to 16, ± perforate at tips, finely and densely papillose to papillose-striate, reflexed or erect and flexuose; endostome segments 8 or lacking, smooth, reticulate or papillose-striate, incurved; preperistome never present.  Calyptra smooth, hairy, mitrate, short-conic to conic, not plicate, usually deeply split several times at base.  Spores isomorphic.


Species ca. 60 (9 in the flora): temperate in distribution; North America, South America, Europe, Asia, Australia, Pacific Islands (New Zealand).


The genus Ulota consists of approximately 60 species of which over half are restricted to the Southern Hemisphere.  Generally, New Zealand, Japan, and western North America are especially rich in species.  Ecologically the species are primarily found either in wet, shaded coniferous forests, particularly in areas of high rainfall, or in subalpine areas where they grow on small trees. Ulota is closely related to the genus Orthotrichum.  Ulota differs by its conic calyptra shape, highly differentiated basal leaf cells, crisped leaves, superficial stomates, and lack of brood bodies on the leaf lamina.  A few species show a close resemblance to the genus Macromitrium in having creeping stems, similar basal cells and calyptrae. The North American species can be divided into four groups:  (1) dioicous species, producing brood-bodies---U. phyllantha;  (2) species with a single, erect-flexuose peristome and leaves not much crisped---U. drummondii and U. coarctata;  (3) species with a double peristome and the exostome teeth reflexed---U. crispa, U. curvifolia, U. hutchinsiae, U. barclayi, and U. obtusiuscula; and (4) species with creeping branched stems---U. megalospora.


1.  Plants dioicous, rarely fruiting; leaves with apical brood-bodies; maritime habitats . . 9. Ulota phyllantha

1.  Plants autoicous, almost always fruiting; leaves without apical brood-bodies; non-maritime habitats.

2.  Capsules distinctly smaller at mouth than at middle; peristome single; exostome teeth erect, flexuose.

3.  Capsules fusiform, strongly 8-ribbed . . 5. Ulota  drummondii

3.  Capsules clavate or obovate, puckered and lightly 8-plicate at mouth . . 2. Ulota coarctata

2.  Capsules constricted beneath mouth or evenly tapering to seta from mouth; peristome double; exostome teeth reflexed.

4.  Perichaetial leaves clasping seta, rounded, smooth, ligulate . . 1. Ulota barclayi

4.  Perichaetial leaves not differentiated from stem leaves.

5.  Plants differentiated into creeping and upright stems; leaves with filiform-acuminate apex, linear-lanceolate; stomates near middle of capsule; spores 35--60 µm. . 7. Ulota  megalospora

5.  Plants with all branches upright; leaves with acute or obtuse apex, lanceolate or linear-lanceolate; stomates in neck of capsule; spores 16--29 µm.

6.  Leaves straight, erect-appressed when dry, not crisped or contorted . . 6. Ulota hutchinsiae

6.  Leaves flexuose, crisped, or contorted when dry.

7.  Plants growing on rock; leaves flexuose but not contorted or twisted when dry . . 4. Ulota  curvifolia

7.  Plants growing on trees; leaves contorted, crisped, or twisted when dry.

8.  Interior basal cells thin-walled, rectangular, not colored; calyptra sparsely hairy; leaves flexuose-crisped when dry

. . . Ulota barclayi

8.  Interior basal cells thick-walled, elliptic-elongate, yellowish; calyptra densely hairy; leaves crisped-contorted when dry.

9.  Plants less than or equal to 4 cm; seta usually equal to or greater than 4 mm; capsules widest at mouth and gradually tapering to seta; leaves contorted and tightly twisted around themselves; western North America . . 8. Ulota  obtusiuscula

9.  Plants less than or equal to 2.5 cm; seta always less than 3 mm; capsules constricted beneath mouth; leaves loosely twisted-crisped, not twisted around themselves; eastern North America . . 3. Ulota  crispa



1.  Ulota barclayi Mitten, J. Linn. Soc. London,  Bot. 8: 26.  1864


Plants to 2.5 cm (usually less than 1 cm).  Stem leaves slightly crisped and curved when dry, narrowly lanceolate to oblong-lanceolate, 1.5--2.5 mm, leaf base oblong; margin broadly reflexed or plane, distal laminal cells 8--12 µm wide, smooth or with small papillae; basal laminal cells hexagonal-rounded, thick-walled.  Sexual condition autoicous.  Seta 1.8--3.2 mm.  Capsule oblong-ovate when mature, oblong-cylindric when old and dry, 1--2 mm, strongly 8-ribbed ± 3/4 length; stomates numerous in neck and proximal portion; peristome double; endostome segments 8, incurved, delicate, caducous; exostome teeth 8, ± split to 16, reflexed, evenly papillose.  Calyptra short-conic, sparsely hairy or with few hairs near apex.  Spores 16--21 µm.


Tree trunks and branches; at low elevations; B.C.; Alaska.  Endemic.


Ulota barclayi, described from Alaska, may or may not be a species distinct from the eastern Asian U. japonica; these species need further study.  From other West Coast species of the genus, these populations differ in leaves only slightly twisted and curved, strongly differentiated perichaetial leaves, cushion-forming erect plants, reflexed exostome, and small spores.


2.  Ulota coarctata (Palisot de Beauvois) Hammar, Mon. Orthotr. Ulota Suec. 25.  1852

Orthotrichum coarctatum Palisot de Beauvois, Prodr. 80. 1805; O. ludwigii Bridel; Ulota ludwigii (Bridel) Bridel


Plants 0.5--1.5 cm.  Stem leaves slightly twisted, erect-curved when dry, narrowly lanceolate to lanceolate, 1.5--2.5 mm; leaf base ovate or oblong; margin reflexed; distal laminal cells 8--11 µm wide, with small conic papillae, sometimes almost smooth; basal laminal cells elongate-linear, thick-walled, sometimes ± nodose.  Sexual condition autoicous.  Seta 1.5--4 mm.  Capsule obovate to oblong-obovoid, 1.1--2.8 mm, puckered, lightly 8-plicate at mouth, otherwise smooth; stomates numerous in neck; peristome single; no endostome segments; exostome teeth 8, splitting to 16, erect, densely and obscurely papillose.  Calyptra oblong-conic, very hairy.   Spores 19--26 µm.


Trunks and occasionally branches of deciduous trees, rarely on conifers; low elevations; N.B., Nfld., N.S., Ont., P.E.I., Que.; Conn., Idaho, Maine, Md., Mass., Mich., N.H., N.J., N.Y., N.C., Pa., Tenn., Vt., Va., W.Va., Wis.; Europe; Asia.


This rather uncommon species prefers climax beech-maple forests, and is distributed from Newfoundland south along the Appalachians to North Carolina and eastern Tennessee, westward in the Great Lakes region to Wisconsin. A disjunctive specimen in northern Idaho (Leiberg, US) is correctly identified, but the location needs to be verified. The obovoid capsules with a strongly puckered mouth are diagnostic for this species.  Ulota drummondii has football-shaped capsules whereas U. crispa has oblong, 8-ribbed capsules constricted beneath the mouth.  Additionally, U. coarctata has non-crisped leaves with clasping bases and acute apices.


3.  Ulota crispa (Hedwig) Bridel, Mant. Musc. 112. 1819


Orthotrichum crispum Hedwig, Spec. Musc. 162: 1801; O. connectens Kindberg; Ulota crispula Bridel; U. connectens (Kindberg) Macoun & Kindberg


Plants to 2.5 cm.  Stem leaves twisted-crisped when dry, narrowly-lanceolate to linear lanceolate, 1.7--3 mm; leaf base ovate, concave; margin plane to reflexed; distal laminal cells 7--10 µm wide, with conic papillae; basal laminal cells linear-elongate grading to quadrate at margin, thick-walled.  Sexual condition autoicous.  Seta 1--3 mm.  Capsule short-oblong to oblong, 0.8--2 mm, strongly 8-ribbed from 3/4 to entire length; stomates numerous in neck and lower 1/3; peristome double; endostome segments 8, smooth; exostome teeth 8, reflexed, densely papillose below, lightly papillose-reticulate above.  Calyptra conic, very hairy.  Spores 23--29 µm.


Common on branches and trunks of trees, especially Betula species; low elevations; N.B., Nfld., N.S., Ont., PE.I., Que.; Conn., Del., Ga., Ill., Ky., Maine., Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio., Pa., R.I., S.C., Tenn., Ver., Va., W.Va., Wis.; Europe; Asia.


This species is distributed from Newfoundland west to Minnesota and south in the Appalachians to northern Georgia, and is not known west of the Mississippi River.  The most common Ulota species, it is easily distinguished by crisped leaves (when dry), capsules contracted beneath the mouth, and a reflexed and well-developed peristome.  Although variable in size, it is smaller than the western U. obtusiuscula and has shorter capsules.  The former species also has flexuose, less reflexed, exostome teeth.


4.  Ulota curvifolia (Wahlenberg) Liljeblad, Utkast. Svensk. Fl. Ed. 3: 546.  1816

Orthotrichum curvifolium Wahlenberg, Fl. Lapp. 365.  1812; O. crispum var. curvifolium (Wahlenberg) Wahlenberg; Ulota americana Mitten


Plants to 0.3 cm.  Stem leaves flexuose-crisped and loosely appressed when dry, lanceolate, 1--2.2 mm, leaf base ovate, narrowly obtuse; margin reflexed, distal laminal cells 8--12 µm wide, with 1--2 large conic or forked papillae; basal laminal cells linear, grading to quadrate at margin, very thick-walled.  Sexual condition autoicous.  Seta 1.5--3 mm.  Capsule ovate-oblong when mature, oblong to oblong-cylindric when old, 1.2--1.7 mm, strongly 8-ribbed for 3/4 length; stomates numerous in neck; peristome double; endostome segments 8, smooth; exostome teeth 8, incurved, smooth.  Calyptra conic, very hairy.  Spores 16--20 µm.


Acidic rock in montane and subarctic areas; 0--2000 m; Greenland; Alta., B.C., Lab., Man., Nfld., Nun., N.W.T., N.S. Ont., Que.; Alaska; n Europe; Asia.


This is a Canadian shield species in eastern North America, which has a range from the northern shore of Lake Huron and Lake Superior north to Hudson Bay and Baffin Island westward across the sub-Arctic of the Northwest Territories and southward in the Canadian Rockies to Alberta and southern British Columbia. This rock-growing species has strongly papillose, thick-walled distal leaf cells and stiffly flexuous leaves.  Ulota hutchinsiae is more southern and has less papillose distal leaf cells and straight leaves.  As with most other species of the genus, U. curvifolia has a rich chestnut brown coloration that helps indicate its identity in the field. 


5.  Ulota drummondii (Greville) Bridel, Bryol. Univ. 1: 299.  1826

Orthotrichum drummondii Greville, Scottt. Crypt. Fl.; Ulota bicolor Bridel; Ulota funstonii Grout


Plants 0.5--1.2 cm.  Stem leaves flexuose to ±contorted-flexuose, loosely erect when dry, lanceolate, 1.7--3.7 mm, leaf base ovate; margin plane or slightly reflexed, distal laminal cells 7--11 µm wide, smooth or slightly papillose; basal laminal cells rounded to elliptic, thick-walled.  Sexual condition autoicous.  Seta 5--5.5 mm.  Capsule cylindric and contracted at mouth when mature, fusiform to fusiform-cylindric when old and dry, 1.7--3.2 mm, 8-ribbed 1/2--2/3 length; stomates numerous in neck and basal portion; peristome single; no endostome segments; exostome teeth 8, splitting to 16, erect and flexuose-incurved, obscurely and densely papillose.  Calyptra conic, very hairy.  Spores 21--24 µm.


Twigs and trunks of conifer and decidious trees, especially in dense coastal forests; low elevations; B.C., Nfld., Que.; Alaska; Europe; Asia.


The distribution of this species is bicentric---it is known from both coasts in North America, from Newfoundland south to Cape Breton and the Gaspé in the East, and from along the Aleutians south to the Queen Charlotte Islands in the West. This species is distinguished by narrowly fusiform capsules that are ribbed almost their entire length and are somewhat smaller at the mouth.  The whitish single peristome is erect and flexuose and easily distinguishes this species from U. crispa with a reflexed exostome.  Additionally, the leaves are blunt and not strongly twisted-contorted.


6.  Ulota hutchinsiae (Smith) Hammar, Mon. Orthogr. Ulot. Suec. 27.  1852

Orthotrichum hutchinsiae Smith, Engl. Bot. 36: 2523. 1813; Orthotrichum americanum Palisot de Beauvois


Plants 0.4--4 cm.  Stem leaves erect-appresssed, stiff, ± slightly curled or twisted around stem, never contorted or crisped when dry, narrowly lanceolate-oblong to lanceolate, broadly acute, to obtuse, 1.4--2.2 mm, leaf base not much differentiated to broad, oblong; margin ±recurved to near apex, distal laminal cells 7--14 µm wide, with small to large, conic to clavate papillae; basal laminal cells rectangular to elongate-rectangular, ± nodose, thick-walled.  Sexual condition autoicous.  Seta 2.5--3.5 mm.  Capsule oblong-elliptic to cylindric-fusiform, 1.1--2 mm, slightly to moderately 8-ribbed 1/3--1/2 length; stomates numerous in neck; peristome double; endostome segments 8, papillose-striate; exostome teeth 8, rarely splitting to 16, reflexed, densely papillose, perforate near tips.  Calyptra oblong-conic, very hairy.  Spores 9--16 µm. 


Varieties 2 (2 in the flora): e and n North America; Europe; Asia.


The species is continuously distributed in eastern North America from Newfoundland and northern Quebec west to western Ontario and south to Georgia and Alabama, and is disjunct in western Arkansas and eastern Oklahoma, the Black Hills of South Dakota, eastern Arizona, and southeastern Alaska.  It is distinguished by erect, non-crisped leaves; cylindric, fully exserted capsules slightly smaller at the mouth and poorly differentiated marginal basal cells.  Ulota hutchinsiae resembles species of Orthotrichum, especially O. anomalum.  That species occurs on calcareous substrates and has capsules with immersed stomates and eight long and eight short capsule ribs.  Ulota curvifolia, another rock-growing species is more northern in distribution and has somewhat twisted and curved leaves.


1.  Leaves 1-stratose, distal leaf cells 8--14 µm wide, with non-incrassate walls and small, conic papillae. . . . 5a. Ulota hutchinsiae var. hutchinsiae

1.  Leaves 2-stratose distally, distal leaf cells 7--10 µm wide, with very incrassate walls and large, clavate papillae. . . .   5b. Ulota hutchinsiae var. rufescens



6a.  Ulota hutchinsiae (Smith) Hammar var. hutchinsiae


Stem leaves acute to narrowly obtuse; leaf base 1-stratose in distal portion; distal laminal cells  8--14 µm wide, with small, conic papillae; basal laminal cells ± nodose, thick-walled. 


Acidic rocks; low to mid-elevations; N.B., Nfld., N.S., Ont., Que.; Ala., Alaska, Ariz., Ark., Conn., Del., Ga., Ky., Maine, Md., Mass., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., S.D., Tenn., Vt., Va., W.Va.; Europe; Asia.


6b.  Ulota hutchinsiae var. rufescens (E. Britton) Dixon, Stud. Handb. Brit. Moss.  244.  1896

Weisia americana var. rufescens E. Britton, Bull. Torr. Bot. Cl. 21: 69.  1894


Stem leaves obtuse; leaf base 2-stratose in distal portion; distal laminal cells 7--10 µm wide, with large, clavate papillae; basal laminal cells very thick-walled.


Tree bases; higher elevations; N.C., Tenn., Va.  Endemic.


7.  Ulota megalospora Venturi in J. Röll, Bot. Centralbl. 44: 389.  1890

Ulota subulata Macoun & Kindberg; U. subulifolia Macoun & Kindberg


Plants 0.5--1.5 cm.  Stem leaves curved, erect-appressed, slightly twisted and ± crisped when dry, linear-lanceolate, 1--2.2 mm, leaf base ovate, concave; margin plane, distal laminal cells 6--10 µm wide, with small, conic papillae, sometimes smooth; basal laminal cells elongate to elongate-elliptic, very thick-walled, not nodose.  Sexual condition autoicous.  Seta 1.5--4 mm.  Capsule short-oblong to oblong-cylindric when old, 0.6--2.2 mm, lightly 8-ribbed 1/3--1/2 length; stomates numerous near middle; peristome double; endostome segments 8, incurved; exostome teeth 8, reflexed, papillose, often reticulate and perforate at apex.  Calyptra conic, sparsely hairy.  Spores 35--60 µm.


Branches and trunks of trees, coastal temperate rain forests; low elevations; B.C.; Alaska, Idaho, Oreg., Wash.  Restricted to nw North America.


This species is distributed along the west coast from northern California, north to northern-most coastal British Columbia, and known inland only in northern Idaho.  It is easily differentiated from other species by having creeping stems with many erect branches (much like a Macromitrium) and leaves with filiform apices.  Also, the stomates are located at the middle of the capsule, not at the capsule base as in other species of the genus.  The spores are large (greater than 35 µm).  It is possible that the Japanese species, U. reptans, also occurs in North America; this species, resembling U. megalospora in growth form but with smaller spores and non-filiform leaf apices, should be looked for.


8.  Ulota obtusiuscula Macoun & Kindberg, Cat. Canad. Pl. 6: 82.  1890

Orthotrichum obtusiusculum (Macoun & Kindberg) Kindberg; Ulota alaskana Cardot & Thériot


Plants 0.1--0.4 cm high.  Stem leaves contorted-crisped, some tightly twisted when dry, linear to linear-lanceolate, 1.8--4 mm long, leaf base ovate, concave; margin reflexed, distal laminal cells 7--13 µm wide, with 1--2 conic, sometimes large, papillae; basal laminal cells elongate, grading to quadrate at margin, with thickened cross-walls, not nodose.  Sexual Condition autoicous.  Seta 2--7(--10) mm.  Capsule oblong to oblong-conic, 1.2--2.5 mm, 8-ribbed for 1/2--3/4 length; stomates numerous in neck; peristome double; endostome segments 8, finely reticulate; exostome teeth 8, reflexed to recurved, densely and finely papillose, perforate in distal 1/2.  Calyptra conic, very hairy.  Spores 24--32 µm.


A common epiphyte in the west coast temperate rain forest; low elevations; B.C.; Alaska, Calif., Oreg., Wash.  Restricted to w North America.


This species has conspicuously twisted and contorted leaves, even when wet.  The long capsules, which are  not much contracted beneath the mouth and peristome, remain erect for much of its maturity.  The plants are larger than those of U. crispa.  It is distributed from northern California north to southern Alaska, occurring inland in western Washington and disjunct in SE British Columbia, whereas U. crispa is confined in North America to the eastern half of the continent, and reports of it from the west are mostly young plants of U. obtusiuscula.  On the west coast, no other species of Ulota has such strongly twisted leaves and forms cushions.


9.  Ulota phyllantha Bridel, Mant. Musc. 113. 1819

Orthotrichum fasciculare Bridel; Ulota maritima Macoun & Kindberg


Plants 0.6--5.5 cm.  Stem leaves contorted-crisped when dry, oblong, lanceolate, or linear-lanceolate, 2--3.5 mm, leaf base ovate, concave; margin narrowly recurved above, revolute below, distal laminal cells 7--10 µm wide, with incrassate walls with 1--2 conic papillae; basal laminal cells linear-elongate, thick-walled.  Sexual Condition dioicious.  Seta 4--5 mm.  Capsule oblong-cylindric, 2--2.5 mm long, 8-ribbed for ± 1/2 length; stomates not seen; mature peristome not seen; endostome segments not seen; exostome teeth 8, papillose.  Calyptra conic, moderately hairy.  Spores not seen.


Tree branches and trunks along the coast, associated with salt-spray; at sea level; B.C., N.B., Nfld., N.S., Que.; Alaska, Calif., Maine, Oreg., Wash.; s South America; Europe; Africa.


This species has twisted-contorted leaves that end in a short-excurrent costa usually covered by dark-brown elongate brood-bodies.  This species is dioicous and rarely has capsules, unlike the other species of the genus that are almost always with sporophytes.  No other species of Ulota has abundant brood-bodies, however even when these are dispersed, the stoutly excurrent costa forming a short cusp and the maritime habitat should serve to recognize the species. This is a species of both coasts, as it is known from northern California north to southern Alaska and the Alaskan Peninsula in the West and from Maine north to southern Labrador in the East.