taxonID	type	description	language	source
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	materials_examined	Type: — PHILIPPINES. SAMAR, Eastern Samar Province, Taft, Barangay San Rafael, 255 m elev., 10 February 2016, J. T. Adorador 072 (holotype PNH!, isotypes K!, LBC!).	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	diagnosis	Diagnosis: — This species is is distinguished from Calamus discolor Martius (1838: 341) in its more slender habit, leaf sheath with scattered straw-coloured acicular spines over thin grayish-white scurfy indumentum, shorter thinly scarious ocrea, very short petiole, fewer leaflets per side of rachis that is furnished above with short bristles along the proximal part of the midrib, apical leaflet pair joined up to half of its length and each segment being relatively the broadest leaflet along the rachis, less-branched pistillate inflorescence, and non-cupular persistent calyx.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	description	Clustering, very slender rattan, climbing to at least 8 m; stem with sheaths to 9 mm diam., without sheaths 4 – 7 mm diam.; internodes to 14 cm long. Leaf sheaths dull green, polished with grayish-white scurfy indumentum with rather few scattered solitary slender, acicular, straw-coloured spines, typically less than 2.4 cm long, up to 3.8 cm along margins near the mouth; flagellum at least 1 m long; knee slightly bulged, generally unarmed; ocrea 3.5 – 4.5 cm long, thinly scarious, readily tattering into fibers. Leaf ecirrate, to 29.5 – 45 cm long, petiole absent or very short to ave. 5 mm long, 3 mm wide; rachis flat then bifacial distally above and armed with stout rigid spines up to 4 mm long which extends into lower portions of leaflets’ midrib, concave then flat distally below and armed with single recurved claw which diminish towards the apex; petiole and rachis of leaves near shoot apex usually covered with sparser grayish-white to light brown scurfy indumentum; leaflets 11 – 16 on each side of the rachis, regularly arranged and spaced 2.7 – 3.3 cm apart, linear-lanceolate to slightly obovoid, apices ± apiculate, 1 - (sub 3 -) costulate, green above and white below, armed with very short bristles along the margins and mid-vein on the adaxial surface, and rather smooth or rarely with bristles on distal portions along midrib on the abaxial surface; transverse veinlets inconspicuous; proximal leaflets 5.4 – 11.5 × 0.4 – 1 cm; middle leaflets to 13.7 – 18 × 1 – 1.7 cm; apical leaflets to 10 – 14 × 1.2 – 2 cm joined up to 2 – 5.7 cm at their bases or at least about 1 / 3 their length. Inflorescence diverging from sheath near the sheath apex. Staminate inflorescence erect or arcuate, 47 – 63 cm long, weakly flagelliform, branching to 2 orders (or up to 3 orders in most basal axes), main axis and rachis armed with up to 2 mm downward-pointing spines; with up to 3 partial inflorescences (first order branches), 12 – 19 cm apart; peduncle up to ca. 27 cm long, 0.5 cm diameter at the insertion on the leaf sheath; prophyll tightly tubular 12.5 – 26 cm long, sparsely armed as the sheath; peduncular bract absent; other primary bracts on the axis similar but decreasing in size towards the apex, covered with whitish scaly indumentum and with short slender spines grouped along vertical portion below the limb, each subtending a partial inflorescence (first order branch), most proximal partial inflorescence to 9 – 11 cm long, erect to slightly arcuate, gradually decreasing in length towards apex of main inflorescence axis, bearing equally-spaced unarmed bracts to 2.3 × 0.3 cm, each subtending rachillae, with up to ca. 10 rachillae on whole axes; rachilla to ca. 3.6 cm long, arcuate, bearing up to 11 staminate flowers on each side, rather congested, rachilla bract less than 1 mm long. Staminate flower to 3 × 2 mm, somewhat pointed in bud; calyx lobes 3, each 1.5 mm, striate, apiculate, joined to basal half; corolla tubular with 3 striate, apiculate lobes to 2 mm high; stamens 6, anthers dorsifixed, filaments to 1.5 mm long; pistillode minute. Pistillate inflorescence as the staminate but generally shorter, to 43.5 – 47 cm long and branched to 2 orders only, with 1 (– 2) partials to 7.5 cm long, main axis and rachis armed with up to 2 mm downward-pointing spines; primary branch bract 1.6 × 0.2 cm, each subtending 4 – 5 rachillae, each to 1.7 cm long, with up to 6 pistillate flowers on each side of the axis; proximal floral bract 2 mm wide, distal floral bract 1.8 mm wide, rachillae bract to 5 mm long, with triangular limbs. Pistillate flower not seen, persistent calyx in immature fruits 2 × 2 mm, fused-cylindrical truncate and non-cupular in basal half, 3 - parted in upper half. Fruit yellowish-green, narrowly-obovoid, 1 × 0.5 – 0.7 cm, stigmatic remains forming a 2 mm high cylindrical beak, with up to 16 vertical series of scales, grooved along the middle, margins ± lacerate; immature seed plano-convex, 5 × 3 × 1.5 mm, the convex side with rough surface, the plane side ridged; endosperm seemingly homogenous. (Figures 1 & 2).	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	distribution	DISTRIBUTION: — Endemic to the Philippines (Samar and Siargao Islands) (Figure 3).	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	materials_examined	SPECIMENS EXAMINED: — PHILIPPINES. SAMAR: Eastern Samar Province, San Rafael, Taft, 255 m elev., 10 February 2016, J. T Adorador 072 (holotype PNH!, isotypes LBC!, K!), 15 June 2019, J. T. Adorador 133 (PNH!, CAHUP!, K!). SIARGAO: locality not known, June 1919, M. Ramos & J. Pascasio 34833 (US! [US 00013173], P! [P 02147169], K!)	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	biology_ecology	HABITAT AND ECOLOGY: — On Samar Island, it occurs near the summits of karst formations (ave. 250 m elev.) in San Rafael, Taft, Eastern Samar. The populations encountered thrive well on edges near forest clearings. The canopy of the surrounding vegetation is about 15 – 20 m high which is formed by large-diameter (ave. 50 – 60 cm diam.) trees. Other Calamus species observed occuring sympatrically include C. discolor, C. merrillii [(= C. zollingeri subsp. merrillii in Henderson (2020 ))], C. multinervis [= C. moseleyanus in Henderson (2020)], C. ochrolepis, and C. symphysipus.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	conservation	CONSERVATION STATUS: — Critically Endangered [CR B 2 b (iii, iv, v) c (iv)]. The area of occupancy (AOO) in Samar and Siargao Islands is estimated to be just 8 km 2. Limited palm surveys in Samar Island Natural Park (SINP) last February 2016 in two 20 m × 20 m nested plots in the type locality, altogether recorded just 21 palm individuals (14 mature and 7 saplings) (Adorador 2016 unpublished data). The low number of mature individuals and continued forest disturbance caused by illegal poaching of forest products (e. g. for fuel wood, drift woods, and ‘ agarwood’ (Aquilaria spp.) only aggravate its survival in the wild.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	etymology	ETYMOLOGY: — The specific epithet comes from ‘ Carsus ’, the Latin term for ‘ karst’ (Kranjc 2011) and ‘ – icola’, a suffix which means ‘ a dweller’ (Stearn 1983); which refers to its preference to the limestone karst habitat.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	vernacular_names	VERNACULAR NAME: — The local guides specifically referred to this palm as ‘ pudlos-uban ’ (Waray). Around Samar Island, the term ‘ pudlos ’ is also applied to several slender rattans such as C. elmerianus [= C. mitis in Henderson (2020)], C. filispadix, and C. usitatus (Adorador & Fernando 2017); while ‘ uban’ translates to ‘ white hair’, in this case the white indumentum on abaxial side of leaflets.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE1A216FF40FDFBFE1BBA41.taxon	discussion	NOTES: — The new rattan only resembles C. discolor in its flagellated leaf sheath, conspicuous ocreas, ecirrate leaf with regularly-arranged discolorous leaflets (green above and white below, but later caducous in C. carsicola). However, C. carsicola is readily distinctive in its scattered straw-coloured acicular spines on the leaf sheath (denselyset longer dark brown acicular spines in partial whorls in C. discolor), the leaf sheath (and all other axes) covered in grayish-white scurfy indumentum (densely appressed with reddish brown lepidote or wooly hairs in C. discolor), shorter and thinly scarious ocrea (up to 4.5 cm vs. longer membranous papery up to c. 20 cm in C. discolor), very short petiole (just 0.5 cm vs. with distinct petiole 4.7 – 35 cm long in C. discolor), fewer leaflets per side of rachis (just 11 – 16 vs. 20 – 50 per side in C. discolor) that is furnished above with short bristles especially along the proximal part of the midrib (typically, with bristles along three nerves above and on midrib below in C. discolor), apical leaflet pair joined at least 1 / 3 of its length (unfused and divergent in C. discolor) and each segment being relatively the broadest leaflet along the rachis (relatively narrower than middle segments in C. discolor), shorter (up to just 47 cm long) flagelliform pistillate inflorescence with few (4 – 5) rachillae per partial (vs. 63 – 150 cm long bearing up to 20 rachillae per partial in C. discolor), and the fused cylindrical truncate non-cupular calyx in fruit (conspicuously bulged cupular in C. discolor). Notably, the novel species is nearest to the diminutive forms of C. discolor that were collected from highelevation serpentine habitats of Mt. Redondo on Dinagat Island (E. S. Fernando 4216 B at LBC) and Mt. Hamiguitan in southeastern Mindanao Island (E. S. Fernando 1634 at LBC), but C. carsicola can be easily separated by the characters stated above. Meanwhile, the little-known C. discolor var. negrosensis Beccari (1909: 635) (variety not recognized in Henderson 2020) differs from C. carsicola in its more spiny sheath, the leaflets being bristly on just the midnerve above and 3 – 5 nerves below, and the apical leaflet pair being divergent and not fused. It is noteworthy that the type specimen of C. discolor var. negrosensis (Danao FB 12432 at FI) consists of the distal portions of its leaf while the staminate inflorescence clearly belongs to C. aidae Fernando (1988: 49). This conclusion is supported by the examination of recent collections of C. aidae comprising leaf materials near the type locality of C. discolor var. negrosensis in Negros Island (A. Baja-Lapis 620 at EBL – hence a new island record) and a staminate inflorescence from Samar Island (J. T. Adorador 061 at LBC) which is hitherto unknown. Several sterile specimens conforming the leaf of C. discolor var. negrosensis have been collected from limestone habitats on islands of Cebu (D. A. Madulid & E. J. Reynoso 5054 deposited at PNH) and Masbate (E. S. Fernando & B. D. Arizala 333) and from cultivated plant in MBG deposited at LBC (E. S. Fernando 1819). Although apparently distinct from the typical C. discolor, we refrain from formally elevating it to species level until complete fertile collections are made and examined. Other closely-related rattans with discolorous leaflets include C. aidae and C. bicolor Beccari (1913: 126). However, these rattans differ from the new species in their much robust non-flagellate leaf sheaths, dense acinaciform spinescence in partial whorls, subcirrate (in C. aidae) or cirrate (in C. bicolor) leaves with very numerous leaflets, and much larger inflorescences.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	materials_examined	Type: — PHILIPPINES. SAMAR, Samar Province, Paranas, Barangay Tenani, 388 m elev., 06 February 2016, Adorador 055 (holotype PNH!, isotype LBC!)	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	diagnosis	Diagnosis: — This rattan is most similar to C. microsphaerion Beccari (in Perkins 1904: 45) but differs in its clustering habit, axillary shoots emerging from cut stem, unarmed rachis below at the proximal half, much fewer and shorter lanceolate leaflets that is typically arranged in divaricate pairs, and relatively shorter rachillae of staminate inflorescence.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	description	Clustering, very slender rattan, climbing to 10 m or more; stem with sheaths 4 – 9 mm diameter, without sheaths to 3 mm diameter; internodes 6 – 9.5 cm long. Leaf sheaths dull green, with sparse bulbous-based, narrowly-triangular, sometimes ± wavy, straw-coloured, laminar spines ave. 1.8 cm long, up to 2.5 cm long near leaf sheath mouth; knee bulged, generally unarmed; ocrea inconspicuous up to 2 mm long. Leaf cirrate, to 70 cm long, including very short petiole to 1.3 cm (typically shorter or absent) and cirrus at least 23 long cm; rachis yellowish, rounded on both surfaces, unarmed above, armed below on the up to at least the distal 1 / 2 its length, distally with single to 2 – 3 claws; cirrus armed with reflexed rigid spines below aggregated into grapnels; leaflets to about 15 on each side of the rachis, typically arranged in 2 ’ s (rarely regularly arranged upon total exposure to light above the canopy) and spaced 3.8 – 7 cm apart, short linear-lanceolate, apices narrowly apiculate, 1 - (sub 3 -) costulate, green and concolorous on both surfaces, glabrous on either surfaces and along margins; transverse veinlets inconspicuous; proximal leaflets 5.2 – 9.5 × 0.4 – 1.3 cm; middle leaflets 5.7 – 13.6 × 0.5 – 1.3 cm; distal leaflets 4.6 – 13.2 × 0.4 – 0.7 cm, distal pair divergent. Inflorescence diverging from sheath way below the sheath apex. Staminate inflorescence arcuate, diffuse-paniculate, 43 – 78 cm long, branching to 3 orders, with up to c. 9 partial inflorescences (first order branches); peduncle 12 cm long, ca. 6 mm diameter at the insertion on the leaf sheath; prophyll tightly tubular to 6.8 cm long, unarmed; peduncular bract 1, 5.5 – 6.5 × 0.6 cm, similar to prophyll, other primary bracts on the axis similar but decreasing in size towards the apex, each subtending a partial inflorescence (first order branch); most proximal partial inflorescences to 22 – 60 cm long, arching, bearing equally-spaced unarmed bracts 3.5 × 0.5, each subtending a second-order branch which bears to ca. 14 rachillae; rachillae to 0.5 – 1.2 cm long (rarely longer, in most basal axes), arcuate, subtended by a bract 8 × 4 mm, with a short triangular limb, bearing up to 12 staminate flowers on each side, rather congested, rachilla bract to 1 mm long. Staminate flower to 3.5 × 2.5 mm, rounded in bud; calyx to 2 × 2 mm, lobes 3, apiculate, joined about half its length; corolla 3 × 2 mm; stamens 6, anthers dorsifixed, filaments to 1.5 mm long; pistillode minute. Pistillate inflorescence as the staminate but generally shorter, to 16 – 51 cm long and branched to 2 (rarely 3) orders only; prophyll up to 5.6 × 0.5 cm; peduncular bract 1, 3.2 × 0.4 cm; partial inflorescences 3 (rarely up to 9), the most proximal up to 14 cm long; primary branch bract up to 2.7 × 0.2 cm; bracts subtending rachillae 4 × 2 mm, with triangular limbs; rachillae up to 4 – 5 on each side of the axis, each 1.6 – 4 cm long, with up to 6 pistillate flowers on each side of the axis. Pistillate flower not seen. Fruit and seed not seen. (Figures 4 & 5).	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	distribution	DISTRIBUTION. Endemic to the Philippines (Samar Island) (Figure 6).	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	materials_examined	SPECIMENS EXAMINED: — PHILIPPINES — SAMAR: Samar Province, Paranas, Tenani, 18 July 2015, J. T. Adorador 022 (LBC!), 388 m elev., 06 February 2016, J. T. Adorador 055 (holotype PNH!, isotype LBC!), 056 (EBL! LBC!), 057 (LBC!, K!), 058 (LBC!).	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	biology_ecology	HABITAT AND ECOLOGY: — Among the karst peaks surveyed, it is only found around the summit of a single karst formation (388 m elev.) in Tenani, Paranas, Samar. It occurs abundantly on the forest floor and canopy of the said summit. The canopy of the surrounding vegetation is about 5 – 20 m high which is dominated by spindly trees (ave. 10 - 20 cm diam.). Other Calamus species thriving sympatrically with this new species include C. discolor, C. multinervis [= C. moseleyanus in Henderson (2020)], and C. ochrolepis.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	conservation	CONSERVATION STATUS: — Critically Endangered [CR B 2 a, b (iii, iv)]. The area of occupancy (AOO) is estimated to be just 4 km 2. In the survey of one 20 m × 20 m nested plot in the type locality, we recorded just 38 palm individuals (13 mature, 17 saplings and 8 seedlings) (Adorador 2016 unpublished data). The said locality has relatively intact forest cover but the low number of mature individuals makes this species very susceptible to extinction, even though it has the capability to produce plantlets on cut stems.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	etymology	ETYMOLOGY: — The specific epithet comes from the terms ‘ Waray ’ which refers to the people inhabiting the islands of Samar, (northern) Leyte and (eastern) Biliran who speaks the Waray-waray language and – anus, a suffix to indicate a sense of belonging or possession (Stearn 1983). This new rattan is named in their honor, especially to the field guides and local community leaders on Samar Island who helped in various ways during the field surveys.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	vernacular_names	VERNACULAR NAME: — It is locally known as ‘ pudlos-liitan ’ (Waray) (Adorador & Fernando 2017). Despite its similarity with other slender rattans locally referred as ‘ pudlos ’, it is said to be the most diminutive hence the term ‘ liitan ’ or ‘ small’.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
03A787F3FFE9A215FF40FEDDFA3EBFE1.taxon	discussion	USES: — This rattan is uncommonly utilized as tying material or as clothesline. NOTES: — This new rattan is most similar to Calamus microsphaerion in its cirrate leaf which typically bears fanned leaflets in definite groups, and staminate inflorescence branched up to three orders. However, C. warayanus differs in its clustering habit (solitary in C. microsphaerion), formation of axillary shoots in cut stems (undocumented in C. microsphaerion), very slender stem (typically more robust in C. microsphaerion), unarmed rachis below up to proximal half of its length (armed with recurved hooks from the leaf base in C. microsphaerion), fewer and significantly shorter lanceolate leaflets (up to 15 per side of rachis measuring 5.7 – 13.6 × 0.5 – 1.3 cm in middle leaflets vs. 19 – 50 linear-lanceolate leaflets and 15.5 – 31.5 × 0.5 – 4.7 cm in C. microsphaerion) which are typically arranged in divaricate pairs (arranged groups of 3 – 7 in C. microsphaerion) and relatively shorter rachillae in staminate inflorescence (up to 1.2 cm vs. 4 – 6 cm in C. microsphaerion). Among the specimens examined, two collections from Mindoro Island deposited at EBL (O. Barile, M. Dimayuga & Co. 639) and at LBC (E. S. Fernando 724 – cultivated at MBG) are arguably the nearest to C. warayanus based on over-all appearance; however details of vegetative and reproductive features refer to that of C. microsphaerion. Likewise, a very similar species to C. microsphaerion, C. malawaliensis J. Dransfield (1982: 805), deviates from the new species in its spinier sheath and rachis, the proximal leaflets being the largest (middle leaflets being the largest in C. warayanus), and significantly shorter pistillate rachillae (up to just 1 cm vs up to 4 cm in C. warayanus). It is very probable that the sterile collection (D. A. Madulid 1003) labelled as C. malawaliensis from Puerto Princesa in Palawan Island is indeed, a C. microsphaerion. The formation of axillary shoots through cut stems is hitherto undocumented (or simply overlooked) for Calamus in the Philippines, while only the aerial and internodal suckering and branching is reported in C. merrillii (Fernando 1987). Similar shoot formation has been documented in other Southeast Asian rattans, but only those that produce plantlets from inflorescence tips (Dransfield 1992, 1997; Henderson & Khou 2013). This asexual mode of reproduction may explain their abundance on the summit of limestone karsts and could be capitalized for their mass propagation.	en	Adorador, Jiro T., Fernando, Edwino S. (2020): Two new species of rattans (Calamus, Arecaceae) from forests over limestone in the Philippines. Phytotaxa 447 (2): 88-102, DOI: 10.11646/phytotaxa.447.2.2, URL: http://dx.doi.org/10.11646/phytotaxa.447.2.2
