SYNGONIUM MAUROANUM
PROTOLOGUE: Syngonium mauroanum , published in Baileya 14: 19 (1966).
Syngonium Mauroanum Birdsey ex Bunting, sp. nov. Lamina foliorum stirpium adultarum profunde tripartita, supra viridis, nitens serici instar, lobo medio elliptico, inaequilaterali, ad 14 cm. longo et 7.2 cm. lato, ad basim apicemque acuminato, utrinque nervis lateralibus primariis ca. 6 in superficie profunde insculptis atque secondariis pluribus cum nervo connectivo a margine pluribus mm. remoto et cum nervulo connectivo secondario margini propinquo conjunctis, nervis omnibus infra valde prominentibus, lobis lateralibus ad 12.5 cm. longis secundum costas, ad 5.8 cm. latis in medio, valde inaequilateralibus, sicut in lobo medio nervatis, latere interno ad 2.1 cm. lato in medio, ad basim acuto-cuneato et cum basi lobi medii sinum parabolicum inter se includente, latere externo multo latiore ad basim plerumque rotundato vel angulari vel hastato-lobato (lobulo ita formato ad 5.5-6.0 cm. longo), costulae basi nuda 1.0-1.2 cm. longa; petiolus ad 24 cm. longus, prominenter vaginatus sub 7-14 cm. infra apicem, parte summa 3-angulata, angulis alulatis. Pedunculi bini 6 cm. longi; spatha ad 13 cm. longa, tubo fusiformi quam lamina leviter breviore, exteriore viridi, interiore in parte inferiore vinario-rubente lamina pallide viridi; spadix 9.3 cm. longus, parte pistillata 2 cm. longa, 1.1 cm. crassa, parte staminata clavata, parte basali sterili 1.7 cm. longa et 1.0 cm. crassa prope basim, sursum angustata ad 0.7 cm. crassa, parte superiore fertili 3.6 cm. longa et ad 1.1 cm. crassa. Holotype: Bunting 1441, cultivated at Amazon Gardens (nursery of S. Mauro), Miami, Florida, 11 Apr 1962 (BH).
DISTRIBUTION: Costa Rica to W. Panama: Costa Rica, Panama.
DISTRIBUTION NOTE: Costa Rica: Guanacaste, Puntarenas Panama: Chiriquí, Colón (Panama), Herrera, Los Santos, Panamá Province, Veraguas.
SPECIES DESCRIPTION:
Nomadic vine to ca. 3 m; juvenile plants with stems at first short, forming rosettes, becoming elongate, green; petioles 6–13 cm long, sheathed to the middle or somewhat above the middle, sharply 1–ribbed from the sheath to the blade; blades sagittate, the primary lateral veins and many secondary veins sunken above and beneath, the upper surface marked along the midrib and sometimes along the larger lateral veins with a discolorous band of gray or yellowish green, the anterior lobe ovate, acuminate, 5–16 cm long, the posterior lobes triangular to ovate, acute to rounded at the apex, 2–10 cm long. Adult plants with stems not glaucous, scandent, appressed to trees; internodes 1–12 cm long, 1.0–1.5 cm wide. Leaves with petioles 6–33 cm long, sheathed 0.5–0.75 their length, free part with a medial rib; blades thin, sub-trisect to usually trisect, rarely 5-segmented, medium green, matte above, slightly paler and matte beneath; leaflets free or sometimes confluent; median leaflet elliptic to ovate-elliptic, (7)12–21(30) cm long, 3.5–10.0(12.0) cm wide, acuminate at the apex, obtuse to acute and attenuate at the base, the margin minutely undulate and sometimes appearing toothed on drying; lateral leaflets inequilateral, sometimes auriculate, the auricle usually conspicuously hastate, narrowly rounded at the apex; primary lateral veins 6–11 per side, distributed throughout the blade (but thicker in the lower half of the blade), conspicuously sunken above, raised beneath; principal, secondary, tertiary and some quaternary veins sunken above, raised beneath, the reticulate veins clearly visible beneath.³
INFLORESCENCE:
Inflorescences 1 or 2 per axil; peduncle 3.5–9.0 cm long and erect at anthesis, 8–14 cm long and pendent in fruit; spathe tube ellipsoid to narrowly ovoid, 3.5–5.0 cm long, 1.5–2.5 cm diam., green outside, dark violet-purple inside; spathe blade ovate-elliptic, 6–8 cm long, 4–5 cm wide, acuminate, white; spadix 6.5–12.0 cm long, narrowly clavate; pistillate portion of the spadix ca. 1 cm long on the back side, ca. 1.5 cm long on the front side; flowers irregularly rhombic at the apex, 2.3–3.0 mm diam., the stigma ca. 1.2 mm diam.; staminate portion of the spadix white, the sterile part ca. 1.5 cm long, the fertile part 5–6 cm long, the synandrium irregularly rounded to rhombic at the apex, the margin irregular, the apex not drying smooth, irregularly undulate. Infructescences 4.5–7.5 cm diam., red on the outside, violet-purple within; syncarp brown, 4.5–6.0 cm long, 2.5–4.0 cm diam.; mesocarp white; seeds ovoid, 5–6 mm long, 4–5 mm diam., dark brown. Flowers are known from April to June and immature fruits in November and January.³
ECOLOGY:
Syngonium mauroanum is known from Costa Rica and western Panama in seasonally dry parts of Tropical moist forest and especially from Premontane moist forest life zones. It is an interesting testimony to the apparent accuracy of the Holdridge Life Zone Maps that the only collection from Costa Rica was also found in a narrow band of Premontane moist forest life zone in Guanacaste and that the species has been collected in the small isolated patch of Premontane moist forest life zone around Santa Fe in Veraguas. The species ranges from sea level to about 500 m elevation.³ altitude: 0–500 m
ETYMOLOGY:
Named in honor of Salvatore ("Sam") Mauro of Miami, Florida, whom Bunting called an enthusiastic plantsman always willing to share his knowledge and facilities. The type was grown at Mauro's nursery, Amazon Gardens, in Miami. The name is Monroe Birdsey's, published by George Bunting in 1966.²
NOTES:
1. The species is a member of Section Syngonium and can be recognized by its usually trifoliolate leaves, hastate-lobed blades with distinctive prominent venation and variegated juvenile leaves. It is not easily confused with any other species because of its relative isolation and narrow ecological range, but the species is closest to Syngonium standleyanum, a species from Premontane wet forest life zone in Guanacaste Province, Costa Rica. That species often shows no sign of auricles on the lateral leaflets (a feature rarely exhibited by Syngonium mauroanum) and has a densely papillate stem. Syngonium standleyanum may ultimately prove to be merely an ecological variant of this species. It may also be confused with Syngonium wendlandii Schott with which it may occur⁵ but that species differs by having finely asperous-striate stems most evident on younger plants, velvety, moderately bicolorous blades with the medial lobe with 3–9 primary lateral veins per side as well as a smaller spadix in contrast to smooth stems, smooth, nearly concolorous leaf blades with 7–11 veins per side.³
2. One of three species proposed in Monroe Birdsey's unpublished 1955 Harvard thesis on the genus; Birdsey's name was published for him by George Bunting in 1966, together with Syngonium erythrophyllum.³
REFERENCES:
1. Plants of the World Online, Royal Botanic Gardens, Kew — Syngonium mauroanum
2. Baileya 14: 19 (1966) — protologue.