Table Of ContentA New Species of Sicydium Schlechtendal
(Cucurbitaceae: Zanonioideae, Zanonieae, Sicydiinae) for the
Flora Mesoamericana
Rafael Lira
Herbario Nacional de Mexico, Departamento de Botanica, Instituto de Biologfa, UNAM,
Apdo. Postal 70-367, Delegacion Coyoacdn, 04510, Mexico, D.F.
Abstract. Sicydium daviliae, from the region of glandular hairs. Stems angulate-sulcate. Petioles
Ocozocuautla, Chiapas, Mexico, is described as angulate-sulcate, l-1.5(-2) cm long; blades
new. It can be distinguished from the other species subcoriaceous, ovate-cordate, 3.5—5.5 cm long, 3—
in the genus by the presence of a soft and dense 5 cm broad, entire, apex acute to shortly acuminate,
pubescence composed of long, multicellular, non- margins entire to slightly undulate-dentate, basal
glandular hairs covering stems, blade surfaces, pet¬ sinus cordate. Tendrils simple. Flowers small, ar¬
ioles and tendrils, by filaments 2—3 times longer ranged in loose panicles. Staminate panicles 4-6
than anthers, by petal margins entire, and by sta- cm long, the branches commonly with a reduced
minate pedicels articulate at the middle or further leaf in the axils; pedicels filiform, 1—1.3 mm long,
up. articulate at the middle or a little above the middle,
subtended by a lanceolate reduced leaf; receptacle
Resumen. Se describe como nueva especie a Si¬ disk-shaped, less than 0.2 mm long, 1-1.2 mm
cydium daviliae, de la region de Ocozocuautla,
wide, puberulent; sepals 5, triangular, ca. 0.6 mm
Chiapas, Mexico. Esta nueva especie se distingue
long, 0.3 mm wide, puberulent; petals 5, ovate-lan¬
de las otras especies del genero por la pubescencia
ceolate, spreading, greenish cream or greenish
densa y suave, compuesta de tricomas largos, mul-
white, 1—1.3 mm long, 0.5-0.6 mm wide, puberu¬
ticelulares y no glandulares, la cual cubre los tal-
lent, the margins entire; stamens 3, totally free, two
los, ambas superficies de la lamina, los peciolos y
with bithecial anthers, one with a monothecial an¬
los zarcillos, ast como tambi£n por presentar fila-
ther; filaments inserted in the base of the recepta¬
mentos 2-3 veces mas largos que las anteras, pe¬
cle, 0.4-0.6 mm long, slightly bent inward, forked
tal os con los mdrgenes enteros y pedicelos estam-
toward the apex in the stamens with bithecial an¬
inados articulados en la mitad o poco mas arriba.
thers; anthers oblong-elliptic, 0.2—0.3 mm long,
opening by a longitudinal suture. Plants with pis¬
As a result of examination of herbarium speci¬
tillate flowers and fruits unknown.
mens for the treatment of Sicydium for Flora Me¬
soamericana, one specimen was found whose sta¬ Sicydium daviliae is known only from the type,
men and vestiture features set it apart as a new collected in the Municipio Ocozocuautla, Chiapas,
species, described below. Mexico, growing in disturbed tropical rainforest at
900 m, on sandy, clayish, and rocky soils.
Sicydium daviliae Lira, sp. nov. TYPE: Mexico. The approximately eight species of Sicydium are
Chiapas: Mpio. Oeozocuauda, Camino Horizon¬ distributed in the Neotropics. They have been tra¬
te a Santa Laura, 12 June 1983, F. Vdzquez B. ditionally distinguished mainly on the basis of sta¬
1024 (male plant) (holotype, XAL). Figure 1. men structure, and presence/absence and distri¬
bution of vestiture (Cogniaux, 1881, 1916; Dieterle,
Sicydio tamnifolio (HBK) Cogniaux similis, sed differt
staminum filamentis quam antheris 2—3 plo longioribus, 1976; Jeffrey & Trujillo, 1992; Nee, 1993; Schle¬
foliorum, caulium, petiolorumque indumento densiore, tri- chtendal, 1832; Wunderlin, 1978). So far, three
chomatibus longis apice non glandularibus constato, pe- species were found in Mexico—Mesoamerica: S.
talorum marginibus integris, florum masculorum pedicellis tamnifolium (HBK) Cogniaux, a species ranging
in parte media vel altiore articulatis.
from central Mexico to South America, and S.
Herbaceous vine, perennial, dioecious, drying tuerckheimii J. Donell-Smith and S. schiedeanum
yellowish green; stems, petioles, upper and lower Schlechtendal (= S. glabrum Standley & Steyer-
surfaces, and tendrils densely pubescent to tomen- mark), both ranging at least from southern Mexico
tose, with long (1—2 mm), soft multicellular, non- to Central America.
Volume 5, Number 3 Lira 285
1995 Sicydium daviliae
0.5 mm
Figure 1. Sicydium daviliae Lira. —A. Habit. —B. Staminate flower. —C. Comparison among the tnchomes present
on the leaves of S. daviliae (1), S. tuerckheimii (2), and S. tamnifolium (3). Based on type specimen F. Vdzquez B. 1024
(XAL).
286 Novon
Sicydium daviliae can readily be distinguished or whitish in dry specimens; filaments ob¬
from the above-mentioned species by its unique solete to 2—3 times longer than anthers.
3a. Plants puberulent to villous, the vesti¬
combination of stamens with filaments 2-3 times ture mainly of glandular hairs; filaments
longer than the anthers; petals with entire margins; obsolete; margins of the petals slightly
a dense, soft indument made up of long, multicel¬ fimbriate or laciniate; pedicels of the
lular, nonglandular hairs; and staminate pedicels staminate flowers articulate near the
that are articulate at or above the middle. In con¬ base . ... S. tamnifolium (HBK) Cogniaux
3b. Plants densely and softly pubescent to
trast, Sicydium tamnifolium includes populations tomentose, the vestiture mainly of non¬
with leaf blades, stems, and petioles densely and glandular hairs; filaments 2—3 times
softly pubescent, but the pubescence is less dense longer than anthers; margins of the pet¬
and the hairs are much shorter and gland-tipped. als entire; pedicels of the staminate
flowers articulate in the middle or
In addition, the stamens of S. tamnifolium have
slightly above.S. daviliae Lira
very short or obsolete filaments, the petal margins
are somewhat fimbriate or laciniate, and the pedi¬ Acknowledgments. I thank the curators of BM,
cels of the staminate flowers are articulate near the BR, CHAPA, ENCB, F, HUH, K, LL, MICH, MO,
base. NY, P. TEX, US, and XAL for allowing me to review
A species with a similar vestiture to that of Si¬ collections of Sicydium, especially Sergio Avendano
cydium daviliae is S. araguense Steyermark & Tru¬ (XAL) for making available the specimen on which
jillo from Venezuela (Jeffrey & Trujillo, 1992). the description of the new species is based. Eloisa
However, in S. araguense the stems are only pu- Duarte prepared the excellent drawings, and David
berulent with age, in adult leaves the pubescence Sutton (BM), Fernando Chiang, and two anonymous
is not as dense or soft, and the leaf blades are nar¬ reviewers commented critically on the manuscript;
rowly lanceolate and longer. The new species is Fernando Chiang also prepared the English version
named to honor Patricia Davila, Mexican agrostol- of the paper, as well as the Latin diagnosis.
ogist.
Literature Cited
Cogniaux, A. 1881. Cucurbitacfes. Pp. 325-951 in A.
A Key to the Mexican/Mesoamerican Species of de Candolle & C. de Candolle (editors), Monographiae
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la. Plants essentially glabrous or only slightly pu- Pp. 1—277 in A. Engler (editor). Das Pflanzenreich.
berulent; leaves always unlobed, usually lustrous Regni Vegetabilis Conspectus. Verlag von Wilhelm En-
in both surfaces; filaments 2-2.5 times longer gelmann, Leipzig.
than anthers.5. schiedeanum Schlechtendal Dieterle, J. V. A. 1976. Cucurbitaceae. In: Flora of Gua¬
lb. Plants conspicuously soft-puberulent, pubescent, temala. Part XL Fieldiana Bot. 24: 306-395.
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bate, not lustrous; filaments obsolete to 3 times Editorial Acta Cientffica Venezolana, Caracas, Venezue¬
longer than anthers. la.
2a. Leaves pubemlent and rough-scabrous on Nee, M. 1993. Cucurbitaceae. In: V. Sosa (editor). Flora
the upper surface, densely and softly pubes¬ de Veracruz. Fasctculo 74. Instituto de Ecologfa A.C./
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commonly dark reddish brown when dry; fil¬ Schlechtendal. D. F. L. 1832. De Plantis Mexicanis. Lin-
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