Archilejeunea fuscescens (Hampe ex Lehm.) Fulford

  • Authority

    Gradstein, S. Robbert. 1994. Lejeuneaceae: Ptychantheae, Brachiolejeuneae. Fl. Neotrop. Monogr. 62: 216. (Published by NYBG Press)

  • Family

    Lejeuneaceae

  • Scientific Name

    Archilejeunea fuscescens (Hampe ex Lehm.) Fulford

  • Type

    Type. Peru (?). "in cortic. Chinae reg.," ex hb. Hampe (holotype, BM; isotype, W).

  • Synonyms

    Phragmicoma juliformis (Nees) Gottsche, Lindenb. & Nees, Lejeunea rufa Spruce, Marchesinia extensa (Steph.) Steph., Archilejeunea spruceana Steph., Archilejeunea juliformis var. unicarinata (Spruce) Gradst. & Buskes, Lejeunea fuscescens Lehm. ex Hampe & Lindenb., Marchesinia fuscescens (Lehm. ex Hampe & Lindenb.) Kuntze, Ptychocoleus juliformis Trevis., Acrolejeunea juliformis Steph. ex Spruce, Jungermannia juliformis Nees, Archilejeunea rufa (Spruce) Steph., Homalolejeunea extensa Steph., Lejeunea unciloba Lindenb., Lejeunea unciloba var. unicarinata Spruce

  • Description

    Species Description - Dioicous. Plants l-4(-6) cm long × 1-2 mm wide, glossy yellow brown to reddish brown to dark brown, creeping, the shoot tips somewhat ascending when fertile. Stems in cross section on average composed of 15 epidermal cells surrounding 18 similar medullary cells; ventral merophyte 4-6 cell rows wide. Leaves imbricate, dorsal lobe suborbicular, 0.8-1.1 × 0.7-0.9 mm, apex rounded to obtuse, plane or recurved, margins plane, ventral margin curved or almost straight forming a sharp or wide angle (90-150°) with the keel, not auriculate at keel junction; median cells about 25-35 µm in largest diam., trigones rather thick, intermediate thickenings 1-3 per cell, one per wall; oil bodies coarsely segmented, Calypogeia-type, bluntly ellipsoid, 8-16 × 4-6 µm, 4-6 in median leaf cells, up to 9 in basal leaf cells. Lobules subrectangular, 1/4-1/2 × lobe length, apex with a sharp, erect or outwardly pointing tooth, the uniseriate tip 2-3 cells long, hyaline papilla positioned at the proximal base of the tooth on the inner surface of the lobule or, when tooth very short, at the free margin. Underleaves imbricate, rarely distant, orbicular or wider than long, 0.5-1 × 0.4-0.6 mm, (3-)4-7 × stem width, apex rounded, recurved or plane, margins plane or recurved, not undulate. Androecia with 6-12 series of bracts. Gynoecia with only one subfloral innovation, bracts about as large as vegetative leaves, lobe apex rounded, lobules lanceolate-acuminate, about 2/3 × lobe length; bracteoles ovate, apex rounded to very short bifid (to 0.07 mm deep). Perianths usually with two ventral keels, sometimes the ventral keels weakly developed or even reduced (var. unicarinata), keels irregularly crenate-denticulate to almost smooth. Sporophyte as in the genus.

  • Discussion

    Chácobo Indians (Bolivia, Dept. Beni) call the species "nihibimi" and prepare a decoction which is drunk against chest pains (Boom, in sched.).

    Archilejeunea fuscescens is one of the most common species of Ptychanthoideae in northern South America and is recognized by its glossy brownish color, appressed growth and suborbicular leaves. The species has been confused with A. porelloides and A. badia but the latter two have more elongated leaves and erect growth.

    Archilejeunea fuscescens varies considerably in size; small plants have been described as A. rufa Spruce. The perianth in A. fuscescens normally has 2 sharp ventral keels, but one or both of these keels may occasionally be reduced. Plants with only one broad ventral keel have been described as var. unicarinata (Spruce) Gradst. & Buskes (see Gradstein & Buskes, 1985, Fig. lc) and are rare. I am not sure whether they merit distinction as a separate taxon.

  • Common Names

    Chácobo Indians

  • Objects

    Pending, G. T. Prance 11868, Unknown, Unknown, Unknown; South America, Brazil, Acre, Cruzeiro do Sul Mun.

    Pending, G. T. Prance 11870, Unknown, Unknown, Unknown; South America, Brazil, Acre, Cruzeiro do Sul Mun.

    Pending, G. T. Prance 11900, Unknown, Unknown, Unknown; South America, Brazil, Acre, Cruzeiro do Sul Mun.

    Pending, G. T. Prance 11901, Unknown, Unknown, Unknown; South America, Brazil, Acre, Cruzeiro do Sul Mun.

    Pending, G. T. Prance 11905, Unknown, Unknown, Unknown; South America, Brazil, Acre, Cruzeiro do Sul Mun.

    Pending, G. T. Prance 11951, Unknown, Unknown, Unknown; South America, Brazil, Acre, Cruzeiro do Sul Mun.

  • Distribution

    Northern South America, particularly in the Amazonia and the Guianas where the species is very common; also collected on Cocos Island (Costa Rica). Archilejeunea fuscescens grows on tree trunks and branches in moist or mesic, primary or secondary rain forests, in the understory and the canopy; occasionally on rotten logs.

    Costa Rica South America| Colombia South America| Casanare Colombia South America| Meta Colombia South America| Venezuela South America| Amazonas Venezuela South America| Apure Venezuela South America| Falcón Venezuela South America| Táchira Venezuela South America| Trinidad and Tobago South America| Guyana South America| Suriname South America| French Guiana South America| Peru South America| Loreto Peru South America| Brazil South America| Acre Brazil South America| Amazonas Brazil South America| Pará Brazil South America| Roraima Brazil South America| Bolivia South America| Beni Bolivia South America|