Diplophyllum domesticum (Gottsche) Steph.
Diplophyllum domesticum var. icari J.J.Engel & Merrill, J. Hattori Bot. Lab. 84: 273. 1998.
Holotype: New Zealand, South Is., Otago Prov., Mt. Aspiring Natl. Park, below and W of Mt. Shrimpton, 1370–1470 m, Engel 17877 (F); isotype: (CHR).
Plants deep reddish orange, the shoots concave in dorsal view; leaves dorsally assurgent, the keel 0.35–0.5 the leaf length, the lobe margins often decolorate and eroded; dorsal lobe often elevated and reflexed distally, 0.5–0.7 the area of the ventral; basal cells in sheathing portion of leaf adjacent to keel typically narrowly elongate (to 5:1), the longitudinal wall often sinuous-thickened; perianth mouth often decolorate and eroded. Oil-bodies occupying a conspicuous portion of cell lumen, hyaline, 6–9 per median ventral lobe cell, coarsely papillose, subglobose to broadly ovoid to broadly elliptic, often somewhat irregularly so, at times with a shallow depression, 5.3–5.8 × 7.2 µm to 3.8–4.8 × 7.2–10.1 µm, spherical ones 4.3–5.3 µm in diam.
Comments : This rather common expression of the species is distinctive, even though it probably intergrades with more typical forms of the species. The dorsal lobes are dorsally assurgent and reflexed and are thus reminiscent of Diplophyllum verrucosum. In the latter plant, however, the dorsal lobe is typically subequal to the ventral, and the leaves have a distinct vitta composed of elongate, often deeply pigmented, thick-walled cells. In D. domesticum the lobe is subvittate, with a less sharply defined broad median field of short-rectangular cells, often extending into the distal portion of the lobe.
