Mitthyridium leucoloma

Click the yellow dot to see these synapomorphies (click any yellow dot to see a clade's characters)

Gemmae characters: gemmae smooth

Margin characters: number of border cell columns evolves from 7 to 30+; margin involute/constricted

Leaf characters: leaf tip rhizoids present

Indel characters: indel 1, 2, 6 and 8 evolve.

Mitthyridium leucoloma

Range Map

This specimen was collected in Australia

Description

Lineage: Mitthyridium leucoloma

Latin name: Mitthyridium leucoloma (C. Mull.) Robinson
Synonyms:
Syrrhopodon leucoloma C. Mull.

General description:
Plants very robust and usually yellow-brown in color. Branches up to 5 cm long. Leaves 3.5-4.5 mm long, 1.5 mm wide with moderately spreading shoulders. The lamina is sagitate, gradually tapered from shoulders into an acute apex, or one that is mildly mucronate. The lamina can be longitudinally plicate, while the margin is typically straight. Stereome (border of hyaline cells) nearly reaching apex and entire along the whole length of the leaf. Costa is percurrent and often reddish. Laminal cells small (5-7 mm wide). Papillae can be present, but are small and few per cell. Cancellinae are wide, often 25-28 cell columns and typically occupy 1/4 the total leaf length. Sporophytes unknown.

Diagnostic phylogenetic characters: [move the cursor over the image to view the morphological matrix]

This is a unique lineage, poorly represented in the samples for the present analyses. That poor representation suggests the possibility that the lineage is fairly rare. Previous authors have synonymized leucoloma with obtusifolium (Reese et al. 1996), though its phylogenetic position suggests that it should be recognized as a distinct evolutionary entity. The number of cell columns are often more than that found in its close obtusifolium relatives (though not more than fasciculatum). The cancellinae/lamina transition shape, state 4, is unique to itself and its relative M. papuanum. The number of marginal border cells composing the stereome is few--on average 10 cells. Papillae are hard to find or absent entirely (though are common in its closest relatives). The costa of leucoloma bears both an adaxial and an abaxial epidermis (as does papuanum).