Tropical Bryology 3: 19-28, 1990 Gradsteinia Andicola, a Remarkable
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View metadata, citation and similar papers at core.ac.uk brought to you COREby provided by Hochschulschriftenserver - Universität Frankfurt am Main 19 Tropical Bryology 3: 19-28, 1990 Gradsteinia andicola, a remarkable aquatic moss from South America Ryszard Ochyra Laboratory of Bryology, Institute of Botany, Polish Academy of Sciences, Lubicz 46, PL-31- 512 Kraków, Poland (Studies on Colombian Cryptogams XLI) Abstract. A new moss genus and species, Gradsteinia andicola, is described from the northern Andes of Colombia. It is an aquatic moss known sterile and characterized by 1) oblong or oblong-ovate, concave, cucullate and recurved-apiculate leaves with a very strong and variable costa that is basically single but commonly repeatedly branched and spurred from the base, giving the leaves a polycostate appearance; 2) thick-walled, porose and irregularly uni- to multistratose lamina cells; 3) bicellular axillary hairs; 4) the presence of incomplete limbidia; 5) the absence of paraphyllia, pseudoparaphyllia, central strand and alar cells. Until the sporophyte of Gradsteinia becomes known, this very distinct genus is tentatively placed in the family Donrichardsiaceae, based primarily upon the presence of variously multistratose leaf laminae and leaf areolation. In the course of my examination of aquatic pleurocarpous mosses for my treatment of the Amblystegiaceae for Flora Neotropica, Gradsteinia andicola Ochyra, gen. & I was surprised by a specimen collected at spec. nov. (Figs. 1-3) altimontane elevations in Colombia that was unlike any of the known genera of Plantae aquaticae, sat robustae, fragiles, aquatic pleurocarps. I feel confident in flavo-virides vel fuscae, nitentes. Caulis proposing a new species and genus for its elongatus, erectus, rigidus, simplex vel inception, although the material available parce irregulariter ramificatus, 13 vel is sterile and sexual organs are not pluria cm longus, pilis axillaribus observed. For reasons discussed below I bicellularibus, paraphylliis et tentatively place Gradsteinia in the small pseudoparaphylliis nullis, in sectione family Donrichardsiaceae, close to transversa ovalis vel ellipticus, e cellulis Donrichardsia Crum & Anderson, until externis 2-3(-4)-stratosis, minoribus, more material and sporophytes become fuscis, parietibus valde incrassatis, internis available. The generic name honours my 4-5-stratosis, magnis, hyalinis, parietibus friend S. Rob Gradstein, the Deputy sat crassis, fasciculo centrali nullo. Folia Director of Cryptogams in the Flora Neo- caulinaria et ramealia similia, sat remote tropica project, and is a tribute to his disposita, siccitate erecto-patentia, contribution to world and in particular curvata vel leviter convoluta, madefacta neotropical bryology. laxe imbricata, carinato-concava, 20 incurvata, non decurrentia, (1.1-)1.7-2.0 central strand absent; paraphyllia absent; mm longa, (0.4-)0.6-0.8 mm lata, oblonga buds scattered along stem or in leaf axils, vel oblongo-ovata, apice rotundata, consisting of a small branch primordium cucullata minute recurvato-apiculata, covered with reduced leaves; pseudopa- marginibus erectis, integris vel minutissi- raphyllia none; axillary hairs infrequent, me distanter parce serrullata in parte bicellular, brown, short. Stem and branch apicali, cellulis laminae irregulariter leaves similar, shrivelled, curved and rolled fluctuante uni- vel multistratosis, pellucidis when dry, rather distant, irregularly erect- vel obscuris, elongato-hexagonalibus vel spreading to patent, loosely imbricate, oblongo-rhomboidalibus, supra costas navicular and distinctly incurved when lineari-flexuosis, 50-90 µm longis, 7.5- wet giving the stem and branches a 10.5 µm latis, parietibus crassis, porosis, catenulate appearance, (1.1-)1.7-2.0 mm in parte folii infima fuscescenti- long, (0.4-)0.6-0.8 mm wide, non decur- lutescentibus, rhomboidalibus vel breviter rent, usually slightly narrowed at base, rectangularibus, 10-15 µm latis, 15-25 oblong or oblong-ovate, concave, rounded µm longis, parietibus valde incrassatis and cucullate at the apex with most leaves porosisque, cellulis folii angularibus aliis in the upper part of shoots recurved- conformibus, costis validissimis, valde apiculate, mostly eroded and fimbriate in variabilibus, callosis, dorso alatis, cristatis, the older part of the stem and branches; 1/3-4/5 basi folii occupantibus, bifurcis margins entire or distantly minutely vel pluripartitis, basi coalitis, ramis dein serrulate above, plane below, erect to in- divergentibus vel parallelicis, saepissime flexed above, very often with incomplete, iteratim ramificatis et in cellulas laminae multistratose limbidia; lamina cells inconspicue confluentibus, ultramedio vel irregulary uni- to multistratose, with prope folii extremitatem evanescentibus frequent unistratose areas and patches in exarata, limbis imperfectis, crassis, the upper part, giving the leaf surface an polystratosis praedita. Inflorescentia ut uneven and ragged appearance, smooth sporophyta ignota. or slightly prorulose, thick-walled and porose almost throughout, linear- Plants moderately robust, in lustrous, dense hexagonal to oblong-rhomboidal, straight tufts, typically stiff, fragile and wiry in to somewhat flexuose, attenuate or oblique texture when dry, light to yellowish-green at the ends, 50-90 µm long, 7.5-10.5 µm above, brown to blackish-brown and wide, becoming shorter, rhomboidal, 20- usually incrusted with silt below. Stems 40 µm long at the extreme apex and up to 13 or more cm long, erect-ascending, narrower, 5-7 µm wide, at the margins; sometimes prostrate to suberect, not cells at the insertion uni- to multistratose, radiculose, terete and distinctly catenulate short rectangular, 10-15 µm wide, 15-25 when wet, often attenuate, simple or µm long, with strongly incrassate and sparsely, freely or sometimes fastigiately porose walls, yellow to intensively orange- branched, usually proliferous because of brown on older leaves; alar cells not repeated annual growth from innovations differentiated, short rectangular to formed below the inactive apical cells and subquadrate; costa very difficult for ob- stretching to nearly the same direction as servation and interpretation, imperceptibly that of the preceding stem, light brown merging into multistratose lamina cells, below, green above, in transverse section basically single but more often forked rounded or elliptic, consisting of 2-3 or, in from the large multistratose base occupying places, 4-5 rows of small, rounded cortical 1/3-4/5 the leaf base with 2 main branches, cells with strongly incrassate, light brown divergent or parallel above, ending in the walls surrounding 3-5 rows of large, upper part of the lamina or extending to hyaline, thick-walled medullary cells; the apex, forming distinct crests on the 24 dorsal surface of the leaves and numerous visible in transverse section of the leaves lateral spurs and secondary branches (Fig. 2). Practically, it is impossible to find usually confluent with each other, even two leaves that are similar to one sometimes situated at the margins and another as regards the system of the uni- giving the leaves a limbate appearance, in and multistratose patches and areas in the transverse section composed of small, laminae. As a rule, however, the basal part thick-walled cells of the same shape and of the leaves is 2-5-stratose and can be size as the adjacent lamina cells. No means interpreted as the base of a costa that of asexual reproduction observed. occupies 1/3-4/5 of the leaf insertion. It is Inflorescences and sporophytes unknown. readily observed as an intensively yellow- or orange brown, obscure area Type: Colombia, Dept. Meta: Páramo de imperceptibly merging on one or both Sumapaz, Hoya Sitiales, lagunita 1 km al sides with the very narrow lamina, which E approx. de la Laguna Sitiales, is merely 1-2-stratose and visible as a temporalmente seco, con Myriophyllum more pellucid, yellow to yellowish-green elatinoides y Ranunculus sp., alt. 3650 m, spot. In addition, limbidia frequently occur 22 January 1973, A.M. Cleef 8236 along the leaf margins. These are salient, (Holotype COL; isotypes BM, F, FLAS, swollen, 3-6-stratose leaf borders of H, KRAM, LPB, MEXU, MO, NY, U). varying width and very irregular shape extending from the leaf insertion to mid- leaf or sometimes as far as the leaf apex, where they coalesce with one another as Discussion well as with multistratose streaks radiating Gradsteinia is a very distinct and unique from the costa. genus immediately recognizable from all The costa itself is difficult to interprete other genera of pleurocarpous mosses by because it is not always clearly delimited, its peculiar leaf structure and costa and numerous spurs and secondary condition. The leaves are loosely imbricate, branches radiating from the main branches concave, boat-shaped and cucullate at the or the basal portion of the costa may apex when wet; when dry, however, they considerably obscure its true nature. are curved and inrolled as well as striate Despite these difficulties the costa can be owing to numerous irregular strands and interpreted as basically single but forked crests on their dorsal surface. Young lea- from the base, as seen in the majority of the ves have a short, distinct and mostly leaves. It usually consists of two very recurved apiculus, while the older leaves strong branches, divergent or rarely on the lower part of the stems and branches becoming above, arising from a are without exception fimbriate and incised polystratose base