Clandarium (Grolle) R.M.Schust.
Blepharidophyllum subg. Clandarium Grolle, J. Hattori Bot. Lab. 28: 65. 1965.
Clandarium (Grolle) R.M.Schust., Phytologia 56: 68. 1984; New Man. Bryol. 2: 984. 1984.
Type: Clandarium clandestinum (Mont.) R.M.Schust. (≡Plagiochila clandestina Mont.)
Plants closely prostrate (except for the erect, microphyllous, gemmiparous shoot apices), usually green or becoming brownish in exposed sites or (Clandarium xiphophyllum) rose-red, to purplish even in shade. Branching sparingly, the branches Frullania type; ventral-intercalary type occasional (?lacking in C. gottscheanum). Stem lacking a clearly defined cortex or (C. xiphophyllum) with a 1-layered hyalodermis + 1–2 interior strata of thick-walled cells. Leaves strongly complanate, distinctly complicate-bilobed, the keel well defined, compressed, locally winged, the primary sinus descending 0.6–0.85, the insertion line narrow, transverse or nearly so in dorsal half; lobes unequal, the dorsal slightly to clearly smaller than the ventral, both lanceolate to ovate or ovate-triangular, shallowly lobulate, the lamina margins copiously ciliate (distally) or spinose-dentate or entire. Cells uniformly thick-walled, without trigones. Oil-bodies dull opaque and hazy in appearance, 2 in nearly all non-ciliiform cells of lobes, obscurely finely papillose. Underleaves lacking in sterile sectors, distinct and to 0.55 the area of leaves in gemmiparous region, in which the leaves are strongly reduced. Asexual reproduction by gemmae, the gemmae in branched chains from lobes of leaves, ovoid to ellipsoidal, 2-celled.
Dioecious. Androecia unknown. Gynoecium terminal on main shoots, those that remain unfertilized nearly always innovated by 1–2(3) ventral-intercalary branches; bracts gradually grading into leaves and scarcely differentiated from them (Clandarium clandestinum) or more strongly toothed than leaves; bracteoles lacking. Perianths long-exserted, somewhat dorsiventrally flattened, especially distally, rather strongly narrowed to the mouth, the mouth somewhat contracted, bilabiate, densely dentate to subciliate, the teeth formed of 1–2 moderately elongated, thick-walled cells that taper toward the summit; perianths multistratose in lower sector. Calyptra polystratose in basal 0.1–0.2 and there with archegonia inserted on it, the distal 0.8–0.9 unistratose, a true calyptra present.
Sporophyte known only in immature state in Clandarium xiphophyllum. Seta massive, with ca. 22–24 rows of outer cells that are ± larger than the internal cells. Capsule ovoid.
For comments see under family.
References: Grolle (1965d); Schuster (1999c, 2002a).
