Syngonium hastiferum (Standley &
L. 0. Williams) Croat, comb. nov.
hastiferum Standley & L. 0. Williams, Ceiba 1:232. 1951.
TYPE: Costa Rica, Puntarenas,
forested hills above Esquinas, in region between Rio Esquinas and
Palmar Sur de Osa, Allen 5563 (US, holotype).
plants hemiepiphytes; stems green, not glaucous, scandent; internodes
to 25 cm or more long, ca. 1 cm diam., drying brown with thin flaking
epidermis; smallest leaves with the petioles sheathed almost to
the apex; blades broadly ovate. Intermediate stages with petioles
20-30 cm long, sheathed to beyond the middle, the unsheathed part
of the petiole terete, becoming weakly flattened laterally toward
the apex; blades becoming elliptic and weakly cordate, finally with
hastate lobes like the adults, then increasing only in size. Adult
plants hemiepiphytic creepers; stems to 2 cm diam. (dried); internodes
ca. 2.5 cm long; petioles to 37 cm long or longer, sheathed ca .
5 /6 their length, the sheath freeending and emarginate at the apex;
blades elliptic-hastate, triangular-acuminate at the apex, deeply
lobed at the base, ca. 40 cm long, 28.5 cm wide, the anterior lobe
ca. 30 cm long, gradually constricted at the base, the sides broadly
rounded, the posterior lobes directed downward or slightly outward,
narrowly triangular, somewhat unequal, the longer lobe to 12 cm
long (from the apex of the petiole to the tip of the lobe), narrowly
rounded at the apex, the shorter lobe to 8 cm long; sinus very narrow
in the apical 2.5 cm, then broadly opening (when flattened), drying
thin, the upper surface brown, the lower surface greenish brown;
midrib flat or weakly sunken, 4 mm wide at the base; primary lateral
veins ca. 13 pairs, weakly raised, the secondary and tertiary veins
clearly visible; principal collective vein 8-12 mm from the margin,
weakly raised on the lower surface; basal veins 3-4 pairs, the basal
rib naked only within 1 cm of the end nearest the petiole.
Inflorescences erect at anthesis, up to 5 per axil;
peduncles 14-15 cm long, 5-8 mm diam. (dried); spathe tube green,
4-5 cm long, ca. 1.3 cm diam.; spathe blade greenish white, ca.
7 cm long, 2.2 cm diam. (unopened), acuminate at the apex, gradually
constricted near the base; spadix sessile, white, 7.5-8.5 cm long;
staminate portion of the spadix more or less ellipsoid, 5.5 cm long,
1315 mm diam., the staminate flowers with the synandrium truncate
and obscurely 4-lobed at the apex, the lobes often obscurely emarginate
at the apex.
Infructescences pendent, yellowish; not seen with mature
fruit. Figs. 9, 10, 159 25.
Syngonium hastiferum is known for certain only from
Costa Rica, principally in the southeast portion in premontane wet,
tropical wet and premontane rain forest life zones. A sterile juvenile
collection from Darien Province, Panama, is believed to be this
species also but lacks the typically narrow sinus. It is recognized
by its entire leaves and relatively small lobes with narrow or often
closed sinus and relatively longer lobes which are usually somewhat
angular and moderately pointed at the apex. The character of rounded
versus angular lobes breaks down to some extent, and plants in Costa
Rican populations can be found, e.g., Croat 32919, which have one
lobe rounded and one lobe angular. Syngonium
hastiferum is similar to S. meridense
which has a broad sinus with relatively
short lobes that are usually rounded. The latter species is restricted
to western Venezuela (Merida). Syngonium hastiferum
is also similar to S. chocoanum
from Choco of Colombia. That species differs in having an open sinus
and a markedly different pattern of venation. In S. chocoanum
the primary lateral veins have conspicuous branches and the tertiary
veins are obscure, close and clearly parallel. In S. hastiferum
the primary lateral veins have no conspicuous major branches and
the tertiary veins are conspicuous, relatively remote from one another,
and markedly wavy. In its venation S. hastiferum appears
similar to S. meridense. Syngonium hastiferum is also
related to S. sagittatum and
S. schottianum but differs
from both by its leaf shape and its smaller inflorescences. In leaf
texture and color it is closer to S. sagittatum.
flowering collections of S. hastiferum have been seen in October.
Immature fruits have been seen in April.
RICA: ALAJUELA: NW of Zarcero, Croat 43579 (MO). PUNTARENAS: Between
Rio Esquinas and Palmar Sur de Osa, Allen 5563 (US); Hills Above
Palmar Norte, Croat 35112 (MO); W of Rincon de Osa, Burger &
Stolze 5532 (NY); Between Palmar Sur and Piedras Blancas, Croat
32911 (MO). SAN JOSE W of San Isidro del General, Croat 32919 (MO);
SW of Rio Pacuare, Croat 35345 (MO).