25. Syngonium mauroanum Birdsey ex Bunting, Baileya 14:18. 1966. TYPE: Panama (exact locality unknown, cultivated at Amazon Gardens, Miami, Florida) Bunting 1441 (BH, holotype).

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, ap-pressed to trees; intemodes 1-12 cm long, 1-1.5 cm wide; petioles sheathed 1/2-3/4 their length; blades thin, subtrisect 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, 12-21(-30) cm long, 3.5-10(-12) 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 6-10 pairs, 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.
Inflorescences 1 or 2 per axil; peduncles 3.5-9 cm long and erect at anthesis, 8-14 cm long and pendent in fruit; spathe tube ellipsoid to narrowly ovoid, 3.5-5 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 6.5-10 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, the flowers irregularly rhombic at the apex, 2.3-3 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 cm long, 2.5-4 cm diam.; mesocarp white; seeds ovoid, 5-6 mm long, 4-5 mm diam., dark brown. Figs. 52, 57, 58.

DISTRIBUTION: Syngonium mauroanum is known from Costa Rica and Panama in seasonally dry parts of tropical moist forest and especially from premon-tane 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 in Guanacaste and that the species has been collected in the small isolated patch of premontane moist forest around Santa Fe in Veraguas. The species ranges from sea level to about 450 m elevation.
The species can be recognized by its usually hastate-lobed blades with distinctive prominent venation. It is not easily confused with any other species because of its relative isolation and narrow ecological range, but the species is closest to S. standleyanum, a species from premontane wet forest in Guanacaste Province, Costa Rica. That species often shows no sign of auricles on the lateral leaflets (a feature rarely exhibited by S. mauroanum) and has a densely papillate stem. Syngonium standleyanum may ultimately prove to be merely an ecological variant of this species.
Flowers are known from April to June and immature fruits in November and January.
COSTA RICA: PUNTARENAS: N Puntarenas, Janzen 10731 (MO); Ujarras de Buenos Aires, Pittier 11121 (US).
PANAMA: CHIRIQUI: Near Remedies, Woodson et al. 1189 (F, GH, MO). HERRERA: S of Ocii, Lewis et al. 1637 (GH, US). LOS SANTOS: Vicinity of Tonosi, Croat 9763 (MO), Lewis et al. 1561 (GH, K, US), Lewis et al. 2193 (MO), Tyson et al. 2954 (MO, SCZ). PANAMA: Vicinity of Panama City, Bartlett & Lasser 16708 (DUKE, MICH, MO). VERAGUAS: Vicinity Santa Fe, Croat 27345, 34249 (MO); E edge of Escuela Agricola Alto Piedra, Croat & Folsom 33981 (MO); Vicinity of Santa Fe, Nee 8038 (GH, MO), Luteyn 4048 (DUKE, MO); S of Santiago, Nee 8231 (MO), Tyson 6045 (SCZ).