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BFNA Title: Plicanthus |
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XX.
PLICANTHUS R.M. Schuster, Nova Hedwigia 74: 484. 2002 * [Latin/greek plica fold, anthos
flower, alluding to the plicate perianth] Chandonanthus Mitten in J. D. Hooker,
Handb. N. Zeal. Fl. 2: 750. 1867 Plants rather robust, but fragile when
dry. Stems in cross section with
firm-walled cells throughout; sometimes with paraphyllia. Lateral leaves squarrose and uneven,
very deeply and asymmetrically 3-fid; lobes abaxially concave, acuminate, and
± spiny; cells with very coarse trigones and occasionally with intermediate
thickenings. Underleaves
symmetrically 2-fid and little smaller than lateral leaves. Asexual reproduction lacking. Sexual condition dioicous. Androecia narrower than vegetative
parts. Gynoecia: perianth strongly
6- to 8-plicate, mouth not tightly closed and longly ciliate. Sporophytes not observed in the
flora. Species
5 (1 in the flora); North America, Asia, Africa, Indian Ocean Islands,
Pacific Islands, Australia. SELECTED
REFERENCES: Schuster, R. M. 2002. Revisionary studies of the
Chandonanthoideae (Jungermanniales, Jungermanniaceae). Nova Hedwigia 74:
465--496. 1. Plicanthus hirtellus (F. Weber) R. M. Schuster,
Nova Hedwigia 74: 492. 2002 Jungermannia hirtella F. Weber, Hist. Musc. Hep.
Prodr. 50. 1815; Chandonanthus
hirtellus (F. Weber) Mitten in B. C. Seemann Plants 30--70(--100) x (0.4--)1.6--2.8(--4)
mm, simple or sparingly branched, ascending in loose mats, yellowish green or
ocher. Stems mostly 300 μm wide, but from 100 to 400 μm, branching terminal of Frullania type (except for
innovations); cells in transverse section firm-walled throughout, gradually
increasing in size from epidermis to the center; no paraphyllia seen,
sometimes slime papillae in the axils of lateral leaves; rhizoids if any, in
loose groups closely below underleaves, hyaline, ca. 11 μm wide. Lateral leaves succubous with oblique insertion, overlapping,
hardly different when dry and wet, squarrose and very uneven, irregularly
quadrangular in outline, very deeply and asymmetrically 3-fid with the
sinuses abaxially protruding, (0.2--)1--1.8(--2) x
(0.4--)1.2--2.2(--3) mm, antical base often with
a small secondary lobe, this and some basal cilia often ending in slime
papillae; lobes unequal, the antical largest, all ± ovate with acuminate
apex, abaxially concave, median lobe about 30--40 cells wide at base, margins
with many spines of various length, the largest lobe often less spinose;
cells somewhat elongated, the subbasal ones (20--)22--38(--41) x (10--)13--20(--22) μm, surface verruculose, cell walls
with coarsely nodulose trigones and intermediate thickenings in the longer
cells; oil bodies 2--4 per cell, ± spherical, botryoidal. Underleaves tranversely inserted and
contiguous, otherwise like the lateral leaves (including the cells), but
somewhat smaller, symmetrical, and 2-fid. Specialized asexual reproduction unknown. Sexual condition dioicous. [Androecia
intercalary, less wide than vegetative parts (1--1.5 mm), length and number
of bracts indefinite, bracts smaller than lateral leaves, saccate, sometimes
with paraphyses, bracteoles without antheridia.] Gynoecia terminal on long shoots, innovations usually 1--2;
bracts ± 4, free and more crowded than leaves of vegetative parts, similar to
these, but somewhat larger and 4-lobed; bracteoles 2, similar to underleaves;
fully grown perianths (only young ones seen in North American specimens)
exceeding the bracts, 3--4 mm, ± fusiform, some antically curved, 6- to
8-plicate, mouth not tightly closed, somewhat lobed, and with several-celled
cilia; ca. 15 archegonia in the perianth. Sporophytes unknown. Humus
under shrubs, cedar forest, dryer places of bogs or rock shelves; mostly with
Herbertus sp.; low to moderate
elevations; B.C.; Asia, Africa, Indian Ocean Islands, Pacific Islands,
Australia. Plicanthus hirtellus is a rare species in North
America confined to westernmost maritime Canada. The few known British
Columbia populations are in the most northern stations worldwide. |
