Mastigolejeunea innovans (Spruce) Steph.

  • Authority

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

  • Family

    Lejeuneaceae

  • Scientific Name

    Mastigolejeunea innovans (Spruce) Steph.

  • Type

    Type. Brazil. Amazonas: Rio Uaupés, Panuré, "ad arborum truncos," Spruce L42 (holotype, MANCH; isotype, BM).

  • Synonyms

    Lejeunea innovans Spruce

  • Description

    Species Description - Autoicous. Plants 2-4 cm long × 2-2.5 mm wide, dull olive-green to blackish-brown. Stems 0.2 mm in diam., in cross section composed of ca, 25 epidermal cells surrounding 60-70 medullary cells, dorsal epidermal cells 1.5-2× larger than other stem cells; ventral merophyte 8 cell rows wide. Leaves when moist strongly convex, dorsal lobe oblong-ovate, 1.1-1.4 × 0.7-0.9 mm, 1.5-1.8× longer than wide, apex rounded or obtuse, plane, ventral margin tilted vertically and upcurved to become hollow, forming a wide angle with the keel; leaf cells in mid-leaf 25-30 × 16-20 µm, trigones usually coarse, intermediate thickenings scarce; oil bodies not observed. Lobules inflated along the keel, l/3-2/5× lobe length, ovate-rectangular, 0.3-0.4 × 0.2-0.25 mm, free margin plane, near apex waving and with 2-3 blunt, triangular teeth tipped by a single cell, the teeth becoming progressively smaller away from the apex, on branch lobules sometimes with only one tooth (type specimen!), apex truncate to oblique, short or continuing into the ventral leaf margin. Underleaves obdeltoid, 0.5-0.6 mm long × 0.6-0.8 mm wide, 3-42× stem width, apex plane, bases slightly auriculate. Androecia usually occupying small, specialized branches with 5-15 series of bracts and bracteoles, rarely terminating an ordinary vegetative branch, bracts small throughout the spike, l/2× leaf length or less, lobules 2/3× lobe length, densely imbricate. Gynoecia with one subfloral innovation, innovations usually repeatedly fertile and gynoecia often in seriate arrangement, sometimes crowded, bracts in one series, obliquely spreading to subsquarrose, lobe oblong, ca. 1.5 mm long × 0.8 mm wide, apex rounded, lobule l/2× lobe length, apex broadly rounded and often retuse-short bifid; bracteole almost as long as the bracts, flat, gibbose, oblong, apex truncate to shallowly emarginate. Perianths immersed or slightly emergent, up to 1.5 mm long, oblong, flattened, sharply 3-keeled with one narrow, high ventral keel, keels smooth or irregularly and bluntly toothed-winged above; beak short, 2-3 cells long. Sporophyte not observed.

  • Discussion

    Conservation. Mastigolejeunea innovans is a rare South American species of Lejeuneaceae and may be considered threatened in view of its restricted occurrence in undisturbed rain forest. There is as yet no reason to classify the species as "endangered" because it occurs in areas where deforestation is not alarming. Moreover, it may be undercollected because of its growth in the canopy of the high forest. The species was classified as rare ("at risk") by Gradstein (1992c).

    Mastigolejeunea innovans is a misunderstood species. The repeatedly innovating stems, which according to Spruce would be the diagnostic feature of the species, are by no means discriminative and are also common in M. auriculata. Mastigolejeunea innovans is excellently characterized, however, by its stem leaves which have lobules with 2-3 teeth (branch leaves may have lobules with only a single tooth!) and by the small, specialized male branches.

  • Distribution

    Brazil (inner Amazonia), French Guiana, at elevations up to 200 m. Mastigolejeunea innovans is a rare species of non-flooded, virgin lowland rain forest of northern South America; probably it is a canopy epiphyte. In French Guiana (Saul) it was found on branches in the outer canopy of a Couratari gloriosa tree, at 30-40 m above the ground.

    French Guiana South America| Brazil South America| Amazonas Brazil South America|