Actinostachys minuta, a new species of grass fern from Mindanao, Philippines Author Amoroso, Victor B. Center for Biodiversity Research and Extension in Mindanao (CEBREM), Central Mindanao University, Musuan, Bukidnon 8710, Philippines & Department of Biology, College of Arts and Sciences, Central Mindanao University, Musuan, Bukidnon 8710, Philippines victorbamoroso@gmail.com Author Coritico, Fulgent P. Center for Biodiversity Research and Extension in Mindanao (CEBREM), Central Mindanao University, Musuan, Bukidnon 8710, Philippines & Department of Biology, College of Arts and Sciences, Central Mindanao University, Musuan, Bukidnon 8710, Philippines Author Fritsch, Peter W. Botanical Research Institute of Texas, 1700 University Drive, Fort Worth, Texas 76107 - 3400, USA https://orcid.org/0000-0002-3606-663X text PhytoKeys 2020 151 59 66 http://dx.doi.org/10.3897/phytokeys.151.53100 journal article http://dx.doi.org/10.3897/phytokeys.151.53100 1314-2003-151-59 54548CADA12B5391B4A97446666E33D7

Table 1. Major characters delineating Actinostachys minuta from A. wagneri, A. spirophylla and A. plana

Character	A. wagneri (Holttum 1955; Reed 1947)	A. spirophylla (Holttum 1955; Reed 1947)	A. plana (Reed 1947)	A. minuta
Habitat	Epiphytic on stumps and bases of trees	Epiphytic in moss-cushions on trees	Epiphytic on tree ferns	Strictly epiphytic on trunks of the tree fern Sphaeropteris polypoda
Stipe	Indistinct	Indistinct	Distinct (5.5-7.5 long mm) flat	Distinct (5-8 mm long) triangular in transection
Lamina (sterile portion) length (cm)	6-20	4-8	5.5-10.2	2.5-3.7
Lamina (sterile portion) width (mm)	0.5-0.7	Ca. 1.5	1.4-1.74	0.8-1.0
Number of stomatal rows on each side of costa	1	1	Not described	1
Sorophore length (mm)	7-15	4-8	2.5-4.8	4-6
Sorophore number	2 to 5	1 to 3	3 to 6 but usually 4	1 to 4 but usually 1
Sorophore lamina apex	Not bifid, glabrous	Not described	Bifid or toothed	Bifid with profuse white long hairs
Sorophore lamina width (mm)	Not described	Not described	0.5-0.8	0.5-0.6 wide
Sporangia	Biseriate with brown hairs	Biseriate (sometimes apparently tetraseriate) and glabrous	Biseriate	Biseriate and glabrous
Spore surface	Striate	Striate	Smooth	Smooth
Distribution	Northeastern Australia, Indonesia (Borneo, Moluccas), Malaysia (Peninsular Malaysia), Papua New Guinea, Singapore, Thailand	Indonesia (Moluccas), Malaysia (Peninsular Malaysia), Micronesia (Ponape)	New Caledonia (Sommet du Mont Mi)	Philippines (Mindanao)