Philodendron josephii C.A.S. Bat. & M.L. Soares sp. nov., 2023

Batista, Caio Augusto Dos Santos & Soares, Maria De Lourdes Da Costa, 2023, Philodendron josephii (Araceae), a new species from central Amazonia, Brazil, Phytotaxa 600 (2), pp. 113-118 : 114-117

Philodendron josephii C.A.S. Bat. & M.L. Soares sp. nov. ( Figs 1 , 2 ).

Philodendron josephii is similar to P. maximum Krause (1913: 49) and P. megalophyllum Schott (1860: 279) in the elongated petiole and the sagittate to hastate leaf blade. However, P. josephii differs in the following characters: petiole tissue dense (vs. spongy in P. maximum and semi-spongy in P. megalophyllum ); leaf blade of flagelliform shoots reddish to vinaceous abaxially (vs. pale green in both the other species); sinus of mature leaf blade 5.0– 7.5 cm long (vs. 24–32 cm and 7–28 cm respectively); ovary locules 8–12 with 12–14 ovules per locule (vs. 5–6 locules with many ovules in P. maximum , and 4–5 locules with a single ovule per locule in P. megalophyllum ).

Type:— BRAZIL, Amazonas state: Rio Preto da Eva , BR-174, Parcelas do PDBFF, acampamento do Cabo Frio ; 2°25’21.50”S, 59°53’49.83”O, 15 October 2021 (fl.), C. A. S. Batista 22 (holotype INPA!, isotype INPA!) .

Plant a climbing hemiepiphyte, reaching 3–15(–20) m in height; juvenile plant usually producing flagelliform branches with elongated, cream-coloured internodes 20–29 cm long, epidermis breaking away in flakes, leaf blade sagittate, adaxial surface glossy green, abaxial surface reddish to vinaceous; juvenile attached climbing stems transversely striate, internodes 4–6 cm long, 0.4–0.5 cm diam., leaf scars 4 cm wide, cream to dark cream; adult flowering stem not forming leaf rosette, internodes abbreviated, 1.0– 2.5 cm long, 0.2–0.8 cm diam., greenish cream; grampform roots 1.3–6.9 mm diam., 4 per node, pale brown when young, dark brown when older, epidermis flaking off, feeder roots ca. 0.5–0.6 cm diam., fibrous, with small, dispersed lenticels, dark green when young, dull dark green when mature, with transparent liquid exsudate having an astringent odour; prophyll 23.5–75.0 cm long, 0.2–0.5 cm diam., pale green to yellowish, somewhat bicarinate, erect to extrorse at apex, with a reddish line on the abaxial surface and small reddish spots over the whole surface. Leaf: petiole 51–111 cm long, dense in texture, pale green, lightly striate longitudinally, adaxial surface invaginate to flattened, abaxial surface semi-cylindric, containing orange resin with strong odour; leaf blade 79–104 cm long, 32–42 cm wide, elongated, oblong, sagittate to hastate, chartaceous, margin sinuate, apex acuminate, base strongly sagittate, usually dilacerated when older, adaxial surface dark green, non-glossy, with primary and secondary veins impressed, abaxial surface paler green with prominent primary and secondary veins, tertiary veins more visible towards the leaf apex, anterior division 54–70 cm long, 22–43 cm wide, primary lateral veins in 6–8 pairs, arising from the midvein at 70° angle, posterior divisions each 25–34 cm long, 13– 21 cm wide, oblong to rounded, apex rounded to acuminate, sinus 5.0– 7.5 cm long, 4–7 cm wide, obovate, acroscopic veins 3, basiscopic veins (2–)3–5. Inflorescence: (2–)3–5(–6) per floral sympodium, cataphyll 10–18 cm long, dark brown, striate, caducous; inflorescence in bud 14.0– 17.5 cm long, pale green, spathe slightly constricted and reddish at margin; peduncle 12–26 cm long, 1–2 cm diam., subcylindric, green, longitudinally striate and more evident near the apex, striate pale green, resin white with sweet aroma; spathe at anthesis 19.0– 27.5 cm long, slightly constricted, entire margin vinaceous, apex acuminate, tube 9.0– 13.5 cm long, 3.5–4.0 cm wide, outer surface pale green, inner surface reddish towards the base with orange resin canals, blade 10–14 cm long, 4.5 cm wide, pale green on outer surface, white on inner surface with resin canals towards the base; spadix 15–25 cm long, 17 mm, base strongly decurrent for ca. 85% of the female zone, stipitate, stipe 0.5–1.0 cm long on ventral side, greenish cream, female zone 3.5–6.5 cm long, 4.6–12.8 mm diam., pale cream, sterile male zone 0.7–1.5 cm long, ca. 5.4 mm diam., pale green to intense yellow with a reddish line at apex, fertile male zone 11–16 cm long, 7.49–12.70 mm wide, subcylindric, pale green to white, apex rounded. Flowers: stamens 3–6 per male flower, each 2–3 mm long, 1.0– 1.5 mm wide; staminode 1 mm long, 2.5 mm wide, prismatic; gynoecium 3.0– 3.5 mm long, 1.5–2.0 mm wide, prismatic; ovary subcylindric; locules 8–12 per ovary, filled with translucid mucilage; ovules 12–14 per locule, 2–3 mm long, hemianatropous; funicle as long as ovule, 2.0– 2.5 mm long, with trichomes in the basal half; placentation axile, biseriate; stigma discoid to capitate. Fruits: unknown; seed unknown.

Additional specimens examined (paratypes):— BRAZIL, Amazonas: Manaus, ASSINPA - clube do INPA, no muro do INPA V8 , 13 December 2021 (fl.), C. A. S. Batista 23 ( INPA 292768 !); Rio Preto da Eva , ARIE PDBFF. Acampamento do Colosso , 2°14’24.00”S 59°47’24.00”O, 4 October 2021 (fl.), C. A. S. Batista 24 ( INPA 292769 !); Presidente Figueiredo, Uatum „: cultivada no Instituto Nacional de Pesquisas da Amazônia-INPA, ao lado do herbário, 1° 0’0.00”S 58°59’60.00”O, 25 May 2021 (fl.), Soares et al. 988 ( INPA 292770 !), 22 July 2021 (fl.), Soares et al. 989 ( INPA 292771 !) .

Distribution, habitat and phenology:—The distribution of this species is so far known only from the localities indicated on the map ( Figure 1 ). It occurs in humid, tropical terra firme forest (forests that are not seasonally flooded by rising rivers) and near streams at altitudes between 50 and 140 m. Inflorescences were seen from May to December.

Conservation Status:— Philodendron josephii is known only for Amazonas state in the municipalities of Manaus, Rio Preto da Eva and Uatum„. It has an EOO of 2.915 km 2 and AOO of 16 km 2, representing 4 subpopulations. The species is thus evaluated with the preliminary status of Endangered (EN): B1a+B2a according to the IUCN categories and criteria.

Eponymy:—The specific epithet honours Dr. Simon Joseph Mayo of the Royal Botanic Gardens Kew, United Kingdom, who has contributed to knowledge of the family Araceae in Brazil, especially in Amazonia, as well as participating in the training and qualification of various Brazilian taxonomists.

Notes:— Philodendron josephii can be recognized in the field by the length and usually yellowish prophyll, the often-vinaceous abaxial surface of juvenile leaves of flagelliform branches, the elongated and dense-textured petioles of adult leaves, the adult leaf longer than wide and usually becoming dilacerated with age. Only the juvenile flagelliform branches show the colour difference. Once the plant has become attached to the supporting tree trunk and no longer has contact with the soil, the vinaceous colour of the leaves is lost as they expand in size. Leaves that do not arise from flagellae, even when juvenile, do not exhibit reddish or vinaceous coloration.

This species can be confused with P. megalophyllum because of the sagittate to hastate leaf blade, peduncle length of 14–23 cm (12–26 cm in P. josephii ) and inflorescence number of 2–5 (3–5 in P. josephii ), but P. megalophyllum differs in its basal placentation and uniovulate ovary locules (vs. axile placentation and 12–14 ovules per locule in P. josephii ). Another species which is has similar leaf blades to P. josephii is P. maximum but the latter species differs mainly by the spongy textured petiole (vs. densely textured in P. josephii ), the width of each posterior division of 30–35 cm (vs. 13–21 cm in P. josephii ), the lack of dilaceration of the mature leaf blade, the 5–6 multiovulate locules per ovary with the ovules inserted along the entire extent of the septum (vs. 8–12 locules per ovary, 12–14 ovules per locule, inserted along only the lower half of the septum to the base). Other taxonomic characters that separate these two species from P. josephii are given in Table 1 .

Figures

FIGURE 1. Philodendron josephii. A. Habit of adult plant; B. Habit of juvenile plant; C. Flagelliform branch; D. Abaxial surface, leaf of flagelliform branch showing reddish coloration; E. Adaxial surface of adult leaf; F. Abaxial leaf surface showing sinus; G. Petiole in transverse section; H. Prophyll; I. Inflorescence showing decurrency; J. Frontal view of fertile stamens; K. Sterile stamen; L. Transverse section of female zone showing locules and apical view of stigmas; M. Gynoecium; N. Ovule.

FIGURE 2. Distribution map of Philodendron josephii.