Monstera limitaris M. Cedeño, 2018

Cedeño-Fonseca, Marco, Karremans, Adam P. & Ortiz, Orlando O., 2018, Monstera limitaris (Araceae), a new species from the border between Costa Rica and Panama, Phytotaxa 376 (1), pp. 37-42 : 38-41

Monstera limitaris M. Cedeño , sp. nov. ( Fig. 1 )

Monstera limitaris is characterized by having leaves with verruculose petioles at base, semi-persistent and convolute sheaths, crenate geniculum margins, blades with pinnatifid margins and fenestrations along the midrib as well as by the white-yellowish acuminate spathe, a creamy-white spadix and flowers with lateral-flattened stigmatophore and linear stigma which have a colorless stigmatic secretion.

Type: COSTA RICA. Puntarenas: Corredores. Canoas. Barrio el Triunfo, margen del Río, 8°33’56,45”N, 82°51’15,48”W, 130 m, 27 de septiembre 2017, M. Cedeño, I. Chinchilla A. P. Karremans & G. Rojas-Alvarado 1129 (holotype: USJ!, mounted on 2 sheets; isotype: PMA!, mounted on 2 sheets) .

Appressed-climber epiphyte herbs. Seedling terrestrial. Juvenile plant with stems adpressed to the host (without blades adhered to the substrate of the phorophyte), stem light green with internodes 3–4 cm long, 4–10 mm diam. Adult plant appressed-climber; Stem terete, brown or beige, internodes 2–3 cm long, 1.5–3.5 cm diam. Roots dimorphic; anchor roots brown, 2–3 cm long; feeder roots light beige, suberous. Leaves numerous, erect or almost erect; petioles whitish, 30–55 cm long, 0.5–1.5 cm diam., dark-brownish verruculose on the base, smooth towards the base of the geniculum, sheathed along its entire length; sheaths semi-persistent, convolute, ligule 2–4 mm long; geniculum with undulate margins, 3–4.5 cm long concave, smooth, abaxially sulcate, adaxially convex; blades sub-ovate to sub-orbicular, oblique, cordate to obtuse at base, acuminate at apex, thinly coriaceous, 35–55 × 20–35 cm, decurrent onto geniculum, with 5–7 undulations of 3–5 mm wide, pinnatifid, the pinnae 3–6 in number on each side; midrib sulcate on the upper surface, convex on the lower surface; primary lateral veins 17–23 per side, bifurcated or trifurcated, sunken above, raised below; tertiary veins reticulated; collective veins prominent; fenestrate usually on both sides, the fenestrae to within 0.2–1.3 mm from the midrib. Inflorescences in ascending stems, 1–3 simultaneously in time of flowering, axillary or subtended by a greenish prophylls; peduncle smooth, 10–15 cm long; spathe 13–18 × 6–10 cm, thin, white at pre-anthesis, white-yellowish externally and white internally at anthesis, open at the apical part forming a tube in the basal region, deciduous after the antesis; spadix 9–12 cm long, 1–2.5 cm diam., white at pre-anthesis, cream at anthesis; flowers 5–6 mm long; ovary 4–5 × 2–3 mm, rectangular and ribbed; style 1–3 × 4–5 mm, hexagonal; stigma 1–2 mm long, linear, stigmatophore lateral-flattened, stigmatic secretion colorless; stamens 4–8 mm long, filament laminar, 2–5 mm long, anther 2–3 mm; sterile flowers not decurrent on the peduncle, 3–5 mm long. Infrutescence erect, fruiting spadix 10–12 cm long, 2–2.5 cm diam.; stylar cap greenish at post-anthesis, white cream at maturity; berries with white pulp; seeds 4–6 mm, lung-shape, black.

Eponymy:—The name limitaris , from the Latin “ limitis ”, refers to a border or boundary, alluding to the type locality, which is on the Costa Rica and Panama border.

Distribution and habitat:— Monstera limitaris is known only from the border between Costa Rica (Puntarenas province) and Panama (Chiriquí province) ( Fig. 3 ). The collection sites consist of isolated trees in open agricultural areas (potreros), on the banks of a small rivers.

Phenology: — Flowering was registered in October and May. Fruiting was registered between October and December.

Conservation status:— Monstera limitaris is restricted to isolated populations in a small geographic area. The habitat where it grows, in both countries, is strongly impacted by human activities, especially due to agricultural expansion. We consider it in the CR B2ab (ii, iii, iv, v) category according to the IUCN Red List Criteria.

Additional specimens examined (paratypes):— PANAMÁ. Chiriquí: distrito de Alanje, Las Moras, creciendo en cerca viva en terrenos semi-inundable, 20 m, 8°21’46’’ N, 82°35’49’’ W, 6 Junio 2018, M. de Stapf 1307 (PMA!, MO!, USJ!, FT!).

Discussion: — According to the classification of Madison (1977), Monstera limitaris must be included in the section Monstera , by having exserted leaves during early juvenile phase as well as for its slender pistils and small seeds. Monstera limitaris ( Fig. 1 , 2 ) is similar to Monstera dissecta ( Schott, 1858: 179) Croat & Grayum (1987: 659) ( Fig. 2 ), but the latter species differs in having leaves with smooth petioles (not verruculose) with persistent and revolute sheaths, non-crenate geniculum margins, blades with entire to pinnatifid margins without fenestrations along the midrib, a yellow-cream spathe externally, semi-conical stigmatophore and orange stigmatic secretion ( Table 1; Fig. 2 ).

In Panama, Monstera limitaris is used by local people for flower arrangements during the religious festivities. The leaves and the inflorescences are placed in all the churches of the town, during the festivities.

Figures

FIGURE 1. Lankester Composite Dissection Plate (LCDP) of Monstera limitaris sp. nov. A. Inflorescence development: B. Frontal and back part-opened inflorescence: C. Infructescence (detachment styling cape): D. Seeds: E. Complete flower (left); cross-section flower (right): F. style and stigma (left); Anther (right): G. Sterile flowers: H. Adult plant: I. seedling.

FIGURE 2. Comparison between Monstera limitaris (A–D), and M. dissecta (E–H). A. Adult plant. B. Brown stem. C. Flower (left); flower in cross section (right). D. Geniculum with crenate margins (upper arrow) and petiole with semi-persistent sheath (lower arrow). E. Adult plant. F. Green stem. G. Geniculum with entire margins (upper arrow) and petiole with persistent sheath (lower arrow). H. Flower (left); flower in cross section (right).

FIGURE 3. Distribution map of Monstera limitaris in Costa Rica (red circle, Puntarenas Province; holotype M. Cedeño et al. 1129) and Panama (black star, Chiriqui Province; paratype M. de Stapf 1307).