Syngonium llanoense Croat, sp. nov.
TYPE: Panama, Canal Zone, Summit Gardens (no doubt collected originally
in Panama or Colon Province), Croat 17148 (MO-219002, holotype).
haud glaucus, ca. 2 cm diam.; foliorum petiolus 9-27 cm longus,
ad apicem vaginatus; lamina oblongata-elliptica, 18-28 cm longa,
8-11 cm lata, apice acuminata, basi rotundata ad subcordata. Inflorescentia
usque 2 in axilla; spathae tubus 5-6 cm longus, ca. 3 cm latus,
viridis; spathae lamina e viridi alba, ca. 10 cm longa; spadix 11.5
cm longa; parte mascula spadicis ca. 9.5 cm longa, alba, parte feminea
spadicis viridi, 2 cm longa, basi 9 mm diam., apice 6 mm diam. (in
plants with trailing stems, the leaves much like those of the adult
but smaller; stems medium green when young, becoming dark olive-green
to purplish; internodes 3-6 cm long, to 6 mm wide, weakly sulcate
above the petioles in the lower part of the internode; petioles
6 cm or longer, sheathed nearly throughout; the sheath 1-1.3 cm
wide when flattened. Adult plants with stems closely appressed to
trees, dark olive-green, shiny, to ca. 2 cm diam., becoming brown
in age, drying with longitudinal wrinkles; internodes to 5 cm or
more long on the lower parts of the stem, 1-3 cm near the apex;
sap pale tan; leaves persisting on the upper 1 m or more of the
stem; petioles 9-33 cm long, broadly sheathed almost throughout,
broadly canaliculate from the end of the sheath to the blade, the
sheath 2-3 cm wide when flattened (to 5 cm wide when subtending
an inflorescence), the margins of the sheath erect at the base,
broadly spreading toward the apex, free-ending and emarginate at
the apex (with the apical lobes sometimes extending beyond the bottom
of the blade); blades simple, oblong-elliptic to ovateelliptic,
gradually acuminate and turned down at the apex (the acumen apiculate),
narrowly rounded to subcordate at the base, 13-34 cm long, 6-13
cm wide, the posterior
lobes 1-2 cm long, held almost erect, rounded at the apex, the upper
surface medium green, matte to semiglossy, the lower surface much
paler, matte; midrib prominently sunken; primary lateral veins 10-18
pairs, sunken above, raised beneath; interprimary veins lew; tertiary
veins distinctly visible; principal collective vein weakly sunken,
4-8 mm from the margin, weakly loop-connected between the primary
Inflorescences usually 2 per axil, erect at anthesis;
prophylls ca. 20 cm long; peduncles 6-8 cm long, the epidermis in
part becoming inflated on drying; spathe tube green, ovoid-ellipsoid,
5-6 cm long, ca. 3 cm diam.; spathe blade greenish-white, ca. 10
cm long, acuminate at the apex; spadix 11.5 cm long (on dried plants);
pistillate portion of the spadix green. ca. 2 cm long, ca. 9 mm
diam. at the base , ca. 6 mm diam. at the apex; staminate and sterile
portions of the spadix 9.5 cm long, white, the sterile staminate
portion ca. 12 mm diam., the staminate flowers mostly ca. 2 mm diam.,
the sterile flowers mostly 4-5 mm diam.
Infructescences pendent; peduncles green, weakly flattened,
to 10 cm long, fruiting spathe oblong-elliptic, 8-10 cm long, 3-4.5
cm diam., fruiting spadix subglobose, ca. 5 cm long, 4 cm diam.,
tan cream; seeds subglobose, ca. 8 mm diam. Figs. 2-4, 21.
Syngonium llanoense was first collected at Summit Garden
but later discovered in both Panama and Colon provinces in areas
adjacent to the Canal Zone. It occurs naturally only in tropical
wet forest life zones.
species is unique among known members of the genus in having oblongelliptic
leaves. Another distinguishing feature is the petiole which is sheathed
throughout its length.
inflorescences have been seen in June and fruits have been found
in June, July, and October.
CANAL ZONE: Summit Gardens, Croat 10831 (DUKE, MO, SCZ), 17148,
35999 (MO). colon: Rio Guanche, Croat 36946 (MO); Vicinity of Rio
Indio, Croat 33636A (MO). panama: El Llano-Carti Road, Croat 25148,
34764, Kennedy 1785 (MO).