IAS on Facebook
IAS on Instagram
Syngonium standleyanum Bunting, Baileya
14:21. 1966. TYPE: Costa Rica, Guanacaste, El Arenal, 485-800 m, Standley
& Valeria 45248 (US-1254001, holotype).
Juvenile plants with scandent stems, not glaucous; internodes 2.3-6.5
petioles sheathed more than 4/5 their length, 4-12 cm long; blades
elliptic, in-equilaterally acuminate at the apex, 4-10 cm long, 2-4
cm wide; intermediate leaves elliptic to oblong or lanceolate, subhastate
or cordate at the base. Adult plants with stems green, not glaucous,
densely and minutely papillate, drying pale brown with longitudinal
wrinkles; internodes 3-12 cm long, less than 1 cm diam.; petioles
25-35 cm long, sheathed 2/3 or nearly the full length (1.5-9 cm from
the apex), the portion above the sheath acutely angled on the upper
side; blades trisect, the leaflets free; median leaflet slightly to
very inequilateral, elliptic to oblong, 18-28 cm long, 6.5-12 cm wide,
acuminate and mucronate at the apex, acute and attenuate at the base;
lateral leaflets elliptic-oblong, 11-24 cm long, slightly if at all
more inequilateral than the median leaflet, acute-cuneate on the inner
edge at the base, obtuse to rounded or slightly auricled on the outer
edge at the base; petiolule 5-15 mm long; primary lateral veins ca.
6 pairs, sunken above, raised beneath; smaller veins clearly visible
(at least on drying).
Inflorescences solitary; peduncle 4.5-5.2 cm long, less
than 4 cm diam. on drying; spathe 11.5 cm long; spathe tube green,
4.5-5 cm long, ca. 3 cm diam., fusiform-cylin-droid; spathe blade
white, ovate-elliptic, 6.2-7 cm long, ca. 2.5 cm diam. (closed), ca.
3.5 cm wide (open), acuminate at the apex, 2.8 cm longer than the
spadix 8.1 cm long; staminate portion of the spadix clavate, creamy
white, ca. 6 cm long.
DISTRIBUTION: Syngonium standleyanum ranges from Honduras to
Costa Rica on the Caribbean slope. In Costa Rica it occurs in tropical
wet forest and premontane wet forest at elevations from near sea level
to about 500 m.
Bunting (1966) reported that the species could be distinguished by
the matte upper blade surfaces, deeply impressed primary lateral veins,
and the shape of the leaf blade. In addition the densely papillate
stem is characteristic. The species is perhaps closest to S.
mauroanum but that species lacks the densely papillate stems,
usually has more prominently hastate posterior lobes, and occurs in
tropical moist or premontane moist forest.
Birdsey (1955) proposed a new species to be called S. stenophyllum
but the name was never published. It was to have been based on Donnell-Smith
6807 (US-936784) and Birdsey 335 (UC, US). I have seen the former
and it is S. standleyanum.
COSTA RICA: GUANACASTE: El Arenal, Standley & Valeria 45248 (US);
Vicinity of Tilaran, Standley & Valeria 44313 (US). LIMON: La
Concepcion, Smith 6807 (US). PUNTARENAS: Osa Peninsula, Parque Corcovado,
Ray 3, 17, 18, 19, 44 (GH).
HONDURAS: ZELAYA: In forest behind Bluefields, Bunting & Licht
1250 (K, US).