Macromitrium ochraceum (Dozy & Molk.) Müll. Hal.

Shevock, James R., 2015, Species of Macromitrium (Orthotrichaceae) New to the Mindanao Region and the Philippines with One Species New to Science, Proceedings of the California Academy of Sciences 62 (21), pp. 541-549 : 547

Macromitrium ochraceum (Dozy & Molk.) Müll. Hal.

SPECIMENS EXAMINED:— Mindanao Island: Bukidnon Province, Mt. Kiamo , along ridge trail to summit in mixed hardwood-podocarp shrubland, on small tree trunk, 7 May 2014, Shevock & B . C . Tan 45171 ( CAS, CMUH, UC); ibid, Mt. Limbawon, trail along ridge top at 1800–1885 m elev. from campsite about 8–9 km distance above Kibalabag village , on ground and branch of Dacrydium in open site of montane forest along a cascading stream, 30 Jun 2015, Shevock et al. 47037, 47041 ( CAS, CMUH, UC) ; Davao Oriental Province, Mt. Hamiguitan , volcanic rock wall, 22 Jun 2015, Shevock & Yorong 46919 ( CAS, CMUH, UC), hardwood branch, 24 Jun 2015, Shevock 46972 ( CAS, CMUH) .

Although this species is not new to Mindanao Island, it was previously known from only a single locality. These collections represent a distribution range extension of this large-sized Macromitrium . Bartram (1939) commented that “the long, ruddy, sparingly branched secondary stems and the very rough setae quickly establish the identity of M. ochraceum ”. According to Vitt et al. (1995), its smooth to slightly bulging, upper laminal cells and the narrowly elongate, straight, thick-walled and tuberculate basal leaf cells add to its species distinctiveness. A good illustration of this species appears in Eddy (1996).

On Mindanao, M. ochraceum is rather variable in its plant size, and, thus, also the coarseness of its stems. In herbarium collections, specimens of M. ochraceum are likely to be misidentified as M. longicaule Müll. Hal. , which has a similarly large plant size, long branches, and curvy, dry leaf foliation. The former species however, has short and papillose setae less than 1 cm long, whereas the latter has smooth setae more than 1 cm long. The leaf cells of M. ochraceum are smooth to mamillose and bulging, not pluripapillose like the leaf cells of M. longicaule . Macromitrium ochraceum is a widespread species at higher elevations in Malesia.