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BFNA Title: Zygodon |
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Zygodon
- Orthotrichaceae 9. Zygodon Hooker & Taylor, Musc.
Brit. 70. 1818 · [yoked (or paired teeth), referring
to the 16 peristome teeth that initially are joined in pairs in some of the
species] Dale
H. Vitt Plants to 10 cm. Stem leaves
loosely-erect and irregularly twisted or curved around stem, sometimes
undulate when dry, erect-spreading to squarrose-recurved when moist,
oblong-lanceolate to linear-lanceolate, 0.5--2.0 mm, acute, usually
apiculate, keeled, decurrent; margins entire or ± denticulate near apex; costa percurrent, ending near
apex, or rarely excurrent; distal laminal cells 4--14 µm wide, densely
pluripapillose, smooth or with 3--6 small, clavate papillae per cell,
somewhat to very thick-walled; basal laminal cells usually yellowish,
subquadrate to rectangular; gemmae elliptic to cylindric or fusiform, 4 to
many celled, axillary. Sexual condition dioicous, autoicous,
or synoicous, rarely with sporophytes.
Seta 3--13 mm. Capsule elliptic-oblong to fusiform,
1--2 mm, strongly 8-ribbed along ±
the entire length, not constricted beneath mouth; peristome double, single,
or lacking; endostome segments 8 or 16, when present; exostome teeth 8 or 16
partially united into 8 pairs. Spores 11--22 µm. Species
ca. 90 (5 species in the flora): North and South America; Europe; Asia,
Africa, Australia, Pacific Islands (New Zealand). Sporophytes
are rarely produced in many species of Zygodon, and taxa are delimited on characters derived exclusively
from the gametophyte. Largely
pan-tropical with several widespread temperate species. None of the species is found farther north
than 60° N latitude. 1.
Distal leaf cells smooth . . . 3. Zygodon
menziesii 1.
Distal leaf cells papillose. 2.
Leaves squarrose-recurved, bluntly acute; distal leaf cells 4--9 µm,
very thick-walled; gemmae never present . . . 2. Zygodon gracilis 2.
Leaves spreading to ± recurved, sharply acute-apiculate;
distal leaf cells 5--14 µm, moderately thick-walled; gemmae always present. 3. Abaxial surface of costa covered by
quadrate, papillose cells only at extreme apex; synoicous . . . 4. Zygodon reinwardtii 3.
Abaxial surface of costa covered by quadrate, papillose cells in
distal 1/3 to 1/2 of leaf; dioicous. 4.
Gemmae fusiform-cylindric, never with transverse walls; distal leaf
cells 9--14 µm wide . . . 1. Zygodon
conoideus 4.
Gemmae clavate to ellipsoidal, with or without transverse walls;
distal leaf cells 5--11 µm wide . . . 5. Zygodon
viridissimus 1. Zygodon conoideus (Dickson) Hooker
& Taylor, Musc. Brit. 71.
21. 1818 Bryum conoideum Dickson, Pl. Crypt. Brit. Fasc. 4:
9. 11 f. 2. 1801 Plants to 0.7 cm. Stem
leaves loosely erect and not contorted when dry, spreading to ± recurved when moist, 1--1.7 mm, oblong-lanceolate,
broadly acute, with abrupt apiculus, usually ending in a long, clear cell;
margins entire; costa ending near apex; distal laminal cells 9--14 µm wide,
with 2--4 small, clavate papillae per cell, somewhat thick-walled; basal
laminal cells pale yellow, subquadrate to short-rectangular; gemmae cylindric
to fusiform. Sexual condition dioicous. Sporophytes not known in North America. Tree
trunks, occasionally on dead branches; low elevations; N.S.; Mass.; Europe. Zygodon conoideus is distinguished from Z. viridissimus by having wider,
oblong-lanceolate leaves, larger leaf cells, and gemmae that have 4--7
horizontal, but no longitudinal septae. 2. Zygodon
gracilis Berkeley, Handb. Brit. Moss. 219. 1863 Plants to 5 cm. Stem leaves
erect-appressed, somewhat contorted and recurved when dry, wide-spreading to
recurved-squarrose when moist, lanceolate to oblong-lanceolate, 1.4--2 mm,
bluntly acute, margins sharply serrate near apex; costa prominent, usually
excurrent or ending obscurely in tip, with distal 1/2 of abaxial side covered
with papillose-quadrate cells; distal laminal cells 4--9 µm wide with 2--4
clavate papillae, very thick-walled, basal laminal cells elongate-rectangular
to short-rectangular; gemmae not present.
Sexual condition dioicous. Sporophytes not known in North America. Restricted
to calcareous rocks; alpine and subalpine regions; B.C.; Central America
(Guatemala). Zygodon
gracilis is
distinguished from other species of
the genus in North America by squarrose-recurved leaves; absence of
gemmae; bluntly acute leaves; and very thick-walled distal leaf cells. 3. Zygodon
menziesii (Schwaegrichen) Arnott, Mem. Soc. Linn. Paris 5: 233. 1827 Codonoblepharon menziesii
Schwaegrichen, Spec. Musc. Suppl. 2(1): 142. 137. 1824; Zygodon drummondii Taylor Plants 0.3--10 cm. Stem
leaves loosely incurved-twisted when dry, erect-spreading to spreading
when moist, oblong, 1.2--1.8 mm, acute; margins entire; costa with abaxial
side covered by quadrate papillose cells at apex; distal laminal cells 7--13
µm wide, smooth, somewhat thick-walled; basal laminal cells
short-rectangular; gemmae fusiform to elliptic, transverse walls absent in
North American material. Sexual condition dioicous. Sporophytes not know in North America. Trees
in the San Francisco area; Calif.; s South America; Australia; Pacific
Islands (New Zealand). The
smooth leaf cells distinguish this species from all others of the genus in
the area. Here for simplicity I have
retained it in Zygodon, but it
probably belongs in a separate genus, Condonoblepharon. 4. Zygodon
reinwardtii (Hornschuch) Bruch, Schimper & W. Gümbel, Bryol. Eur. 3,
fasc. 4 (Zygodon, p. 9). 1838 Syrrhopodon reinwardtii Hornschuch, Nov. Act. Ac. Leop.
Car. 14(2): 700. 39. 1829; Zygodon
reinwardtii var. subintegrifolius
Malta Plants to 2 cm. Stem leaves
irregularly-twisted or curved, loosely spiraled around stem and ± undulate when dry, spreading to wide-spreading,
sometimes subsquarrose, recurved when moist,
oblong-lanceolate to broadly lanceolate, leaves 0.7--2 mm, sharply acute,
usually with a 1 to many-celled apiculus, decurrent; margins entire to ± sharply serrulate near apex; costa slender, ending near
apex; distal laminal cells 5--11 µm wide with 3--6 clavate papillae, somewhat
thick-walled; basal laminal cells short-rectangular; gemmae clavate to
elliptic. Sexual condition synoicous or autoicous. Spores
17--22 µm. Trunks
of trees; low elevations; B.C.; Alaska; Mexico; West Indies; Central America
(Guatemala, Costa Rica, Panama); South America; Asia; Africa; Pacific
Islands; Australia. Identifying
characteristics of this species include (1) leaves entire or ± serrulate at apex; (2) synoicous or autoicous; and (3)
back of costa smooth, not covered with papillose, quadrate cells in distal
1/2 of leaf. The serrulation of the
distal leaf margins is highly variable, with some specimens having sharply
serrulate margins (in the past placed in var. reinwardtii), while others have entire margins or margins with
one or two small teeth (placed in var. subintegrifolius). I doubt the value of taxonomically
distinguishing thes plants. 5. Zygodon
viridissimus (Dickson) Bridel, Bryol. Univ. 1: 592. 1826 Bryum viridissimum Dickson; Pl. Crypt. Brit. Fasc. 4:
9. 10 f. 18. 1801 Plants to 2.3 cm. Stem
leaves loosely-erect and ± spirally twisted to somewhat
contorted, sometimes falcate-secund in distal portions of stems when dry,
erect-spreading to spreading when moist, oblong-lanceolate, lanceolate, or
linear-lanceolate, 0.5--2 mm, acute, with gradual, 1--few celled apiculus, ± keeled below, decurrent; margins entire or with sharp,
irregular teeth near apex, somewhat wavy; costa ending below apex with
abaxial side covered with quadrate papillose cells only at apex; distal
laminal cells 7--11 µm wide, with 2--4 clavate papillae, somewhat
thick-walled; basal laminal cells pale-yellow, subquadrate to rectangular;
gemmae clavate to elliptic. Sexual condition dioicous. Spores
11--15 µm. Varieties
at least 5 (4 in the flora); high elevations; widely scattered in the flora
area, from Alberta. and Quebec south to Massachusetts and California; North
and Central America; Europe; w Asia; Africa; Atlantic Islands (the Canaries). Zygodon viridissimus in the flora includes Northern Hemisphere Zygodon
phenotypes with (1) ovate to elliptic gemmae, (2) narrowly lanceolate, loosely
erect leaves, (3) the abaxial surface of the costae in the distal 1/3--1/2 of
the leaf covered with papillose, quadrate cells, (4) dioicous sexual
conditions, and (5) rudimentary (or no) peristome. The species is generally found on tree trunks and in crevices
on vertical rock faces, usually at high elevations (up to 4000 m in western
N. America). 1.
Leaves serrulate at apex. 2.
Gemmae without curved longitudinal septae; plants less than or equal
to 5 mm. . 5a. Zygodon viridissimus
var. A 2.
Gemmae with curved longitudinal septae; plants greater than or equal
to 5 mm. . 5b. Zygodon viridissimus
var. dentatus 1.
Leaves entire. 3.
Gemmae with longitudinal septae; leaves oblong-lanceolate to
lanceolate. . . 5d. Zygodon
viridissimus var. viridissimus 3.
Gemmae without longitudinal septae; leaves lanceolate to
linear-lanceolate . . 5c. Zygodon
viridissimus var. rupestris 5a.
Zygodon viridissimus var. A Zygodon apiculatus Redfearn, Bryologist 70: 333. 1967 Plants 0.1--0.4 cm, dark-green to brownish. Stem
leaves oblong-lanceolate to oblong-ovate, 0.5--1.3 mm, acute and abruptly
apiculate; margins irregularly serrulate at apex or sometimes entire; brood
bodies elliptic to subcylindric, without longitudinal septae, of 3--5
cells. Sporophyte not known. Trunks
of deciduous trees in dry oak-hickory climax zone; N.C., Mo. This
variety is restricted to the southern Appalachians and Ozark Mountains. It
differs from its closest relative, Z.
viridissimus var. rupestris, by
its small size and serrulate distal leaf margins. 5b.
Zygodon viridissimus
var. dentatus (Juratzka) Limpricht
in G. L. Rabenhorst, Deutschl. Crypt. fl. (4) 2: 12. 1890 Zygodon dentatus Juratzka, Laubmfl. Oest. Ungarn 190.
1882 Plants to 1.7 cm, light green. Stem
leaves ± twisted when dry, oblong-lanceolate
to narrowly-lanceolate, 1--2 mm, acute, usually with ±
gradual apiculus; margins irregularly serrate near apex; brood bodies with
longitudinal septae, septae curved, of 4--9 cells. Sporophytes not
known in North America. Crevices
in vertical rock faces; 3000 m; Ariz.; Europe. This
variety is distinguished by its robust plants, sharply toothed distal leaf
margins, and abundant gemmae having curved longitudinal septae. It has been found in the flora only in the
White Mts. of Arizona. 5c. Zygodon
viridissimus var. rupestris
Hartman, Handb. Skand. Fl. ed 5: 371. 1849 Plants to 2.3 cm, yellow-green,
olive-green, or brownish. Stem leaves linear-lanceolate to
elongate-lanceolate, 1--2 mm; short-acuminate or apiculate apex of 1--3
cells; margins entire; brood bodies elliptic, without longitudinal septae, of
3--5 cells. Sporophytes not found in North America. Trunks
of trees and on rocks; low to middle elevations; Alta., B.C., N.B., N.S.,
Ont., Que.; Ariz., Calif., Mass., Mich., N.Mex., N.Y., N.C., Oreg., Tenn.,
Va., Wash., Wis.; ne Mexico; Europe, n Asia; n Africa. 5d. Zygodon
viridissimus (Dickson) Bridel var. viridissimus Plants to 1.5 cm, light-green to
olive-green, usually with very little tomentum. Stem leaves oblong-lanceolate
to lanceolate, 1--2 mm, short-apiculate; margins entire; brood bodies with
longitudinal septae, septae ± straight, of 5--10 cells. Sporophytes
not found in North America. Trunks
of trees, large, conglomerate boulders; low elevations; N.S., Que.; Europe. This
variety is distinguished by its entire leaves and gemmae with longitudinal
septae. |
