SYNGONIUM HUASTECORUM
PROTOLOGUE: Syngonium huastecorum , published in Phytotaxa 694: 290 (2025).
Syngonium huastecorum Díaz Jim., Pérez-Farr. & Croat, sp. nov. It is morphologically similar to Syngonium podophyllum, but differs from that species in having longer petioles (up to 69.5 cm), medium leaflets with more primary lateral veins per side (9–17 vs. 3–7), fewer inflorescences per axil (1–4 vs. 4–11), inflorescences with longer peduncles at anthesis (up to 13.5 vs. fewer than 10 cm), and staminate flowers lacking a line of fusion between the staminodia (vs. with a distinct line of fusion). Type: MEXICO. San Luis Potosí: Municipio Tamazunchale, Tacial, 21°15'17"N, 098°48'48"W, 186 m, 31 Jul. 2021, Pedro Díaz Jiménez, M. Á. Pérez-Farrera & M. M. Salinas-Rodríguez 1598 (holotype HEM 46906!, isotype CHIP).
DISTRIBUTION: Mexico Northeast, San Luis Potosí.
DISTRIBUTION NOTE: Mexico: San Luis Potosí.
SPECIES DESCRIPTION:
Appressed-climber or hemiepiphyte at 5 m. Juvenile leaves oblong-sagittate, 19–24 cm long, 11–17 cm wide, posterior lobes oblong to ± triangular, 6.5–10.0 cm long, 4.0–7.5 cm wide, rounded at apex. Adult plants with internodes 4–10 cm, 8.0–16.0 mm diam., dark green or dark olive-green, glossy, glaucous, flattened-ribbed on one side, sap milky; roots greenish and brown, up to 4.3 mm in diam. Leaves erect-spreading, petioles 30.5–69.5 cm, 4–7 mm diam., sheathed 1/2–2/3 its length, sheath erect or extended and with a rounded, and slightly free-ending at apex, rarely with a free tip up to 3.8 cm long, with a free portion to 15–20.5 cm from base of blade, terete, obtusely angular adaxially, glaucous, light green, drying dark and light brown; blades trisect or 5-pedatisect, 19.5–35.0 cm long, 21.5–53.0 cm wide, thin, dark green and semiglossy above, light green and semiglossy below, drying dark yellow-brown to greenish above, light brown and greenish below; medial lobe oblong-elliptic, 19.0–34.5 cm long, 8–15 cm wide, up to 2.5 times longer than wide, inequilateral, one side up to 10 mm wider, acute or mucronate at apex, cuneate at base; inner lateral lobes 18–30 cm long, 8.5–11.0 cm wide, only slightly shorter than medial lobes, acute at apex, markedly inequilateral, outer margin, 0.3–3.5 cm wider than inner margin; outermost pair of lobes auriculate at base of outer margin, auricles sometimes becoming free, 7.0–12.2 cm long, 3.0–4.7 cm wide; primary lateral veins sunken above, 9–17 pairs on median segment, whitish below, dark green above, departing midrib at 40–55° angle, drying dark or light brown above and below; tertiary veins fine, slightly visible but not raised below; midrib rounded and light green below, drying brown above and below.²
INFLORESCENCE:
Inflorescences 1–4 per axil, erect at anthesis; prophylls 15–31 cm long, 2-ribbed, light green, drying light brown; peduncle 10–14 cm long, 5.0–11.5 mm diam., subterete or ± flattened, light green to grayish and glaucous, drying grayish; spathe 9.7–10.8 cm long; tube 2.5–3.3 cm long, 1.3–1.8 cm diam., light green and glaucous outside, light green and whitish within, drying dark brown, blade 7.0–9.6 cm long, 5.3–5.8 cm wide, light yellowish outside, whitish within, drying light brown, acuminate or cuspidate at apex, sometimes reflexed at apex, deciduous at post-anthesis; spadix 6.8–8.4 cm long; staminate spadix 3.9–5.2 cm long, 11.0–11.3 mm diam. in middle, white to cream, drying creamy brown, staminate flowers truncate at the apex, 1.1–1.9 mm long, 1.0–2.1 mm diam., with not line of fusion; sterile staminate portion 1.0–1.3 cm long, 5.0–5.5 mm diam.; pistillate portion 2.0–2.2 cm long, 6.0–7.3 mm diam., light green, drying dark brown, pistillate flowers, 2.1–3.0 mm long, 2.0–2.5 mm diam., the stigma discoid., ca. 0.5 mm diam., transparent and glossy. Infructescences immature erect, mature pendent; peduncles 11.5–14.0 cm, light green, dark to yellowish; spathe blade deciduous on immature fruits; syncarp ovoid to ± globose, 5.5–6.5 cm, 3.3–3.5 cm diam., red and glossy when maturity; seeds gray, 5.0–8.2 mm long, 4.5–5.5 mm diam., ± ovoid.²
ECOLOGY:
Syngonium huastecorum is endemic to the municipality of Tamazunchale, in the region known as the Huasteca Potosina. It grows in evergreen sub-deciduous forest at 186 m above sea level. Specimens with inflorescences and infructescences were collected in situ in July, and cultivated plants flowered in September and October.² altitude: 186 m
ETYMOLOGY:
Named for the Huasteca region of San Luis Potosí, northeastern Mexico, where the type was collected. The original description explains that the Huasteca is a biocultural region spanning parts of Tamaulipas, San Luis Potosí, Veracruz, Querétaro, Hidalgo and Puebla, whose communities share traditions of music, food and festivities. The epithet is a Latin genitive plural, "of the Huastecs."²
NOTES:
1. The tenth species of the genus and the eighth of section Syngonium recorded for Mexico, and the fourth for the state of San Luis Potosí.² It is characterised by its long internodes, long petioles, trisect or 5-pedatisect blades, 9–17 pairs of primary lateral veins on the median segment, up to four inflorescences per axil, long peduncles, a spathe blade deciduous after anthesis, staminate flowers truncate at the apex and lacking a line of fusion between the staminodia, infructescences erect when immature and pendent at maturity, and red, glossy syncarps.²
2. It is morphologically similar to Syngonium podophyllum, which has shorter petioles, fewer primary lateral veins per side on the medial leaflet, up to three times as many inflorescences per axil, shorter peduncles at anthesis, and staminate flowers with visible lines of fusion.² It can also be confused with Syngonium neglectum, a Mexican endemic occurring in the same area, which differs in having the spathe tube almost twice as long and almost three times as wide at anthesis, glossy green outside and red or purple to violet within, and a spathe blade that persists in fruit.²
3. The authors suggest that a specimen from Querétaro determined as Syngonium podophyllum (Sergio Zamudio R. 7798, MO) may belong here — its oblong-elliptic medial lobe has more than nine primary lateral veins per side and up to three inflorescences per axil — but say inflorescences at anthesis must be examined to confirm it.²
4. Several slips are printed in the protologue and are transcribed here as published: “with not line of fusion” in the staminate-flower description (the diagnosis on the same page reads “lacking a line of fusion between the staminodia”), “red and glossy when maturity” for the syncarp, a doubled stop in “the stigma discoid., ca. 0.5 mm diam.”, and stray commas in “outer margin, 0.3–3.5 cm wider than inner margin” and “pistillate flowers, 2.1–3.0 mm long”.²
REFERENCES:
1. Phytotaxa 694: 290 (2025) — protologue.