9. Syngonium hastiferum (Standley & L. 0. Williams) Croat, comb. nov.

Philodendron 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).

Juvenile 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.

DISTRIBUTION: 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.

Fertile flowering collections of S. hastiferum have been seen in October. Immature fruits have been seen in April.

COSTA 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).