Vines and Climbing Plants of Puerto Rico and the Virgin Islands

274
Vines and Climbing Plants of Puerto Rico and the Virgin Islands
open in a spiral. Seeds oblong or ovoid, 6-8 mm
long, light brown.
Phenology: Flowering from June to December
and fruiting from November to April.
Status: Endemic, very common.
16. PACHYRHIZUS
17. PHASEOLUS
Distribution: In the moist or wet forests of the
Cordillera Central, the Sierra de Luquillo, and in
the area of mogotes, at middle and upper
elevations.
Public Forests: Carite, Guajataca, Guilarte,
El Yunque, Maricao, Río Abajo, Susúa, and Toro
Negro.
Herbaceous or slightly woody vines, twining, with tuberous roots. Leaves alternate, trifoliolate;
stipels filiform; stipules lanceolate, persistent. Inflorescences of axillary or terminal pseudoracemes,
long-pedunculate; bracts minute. Calyx campanulate, bilabiate, with 5 lobes; corolla blue or violet, the
standard broadly obovate, auriculate, oblong, the wings oblong-falcate, with a curved appendage at the
base of the inner margin, adhering to the keel along the basal portion of the inner margin, the keel as
long as the wings, recurved; stamens 10, diadelphous; ovary superior, subsessile, with many ovules,
the style curved, the stigma globose. Fruit an oblong legume, coriaceous, flattened, dehiscent, the
valves septate internally between the seeds; seeds flattened, with a hilum of reduced size. A genus of 6
species, distributed throughout the Neotropics.
1. Pachyrhizus erosus (L.) Urb., Symb. Antill.
4: 311. 1905.
Fig. 110. A-E
BASIONYM: Dolichos erosus L.
SYNONYM: Cacara erosa (L.) Kuntze
Jícama
Herbaceous vine, twining, attainig 3-10 m in
length. Tuberous roots thick. Stems cylindrical,
slightly ribbed, pilose. Leaves alternate,
trifoliolate; leaflets chartaceous, the apex shortacuminate,
the margins deeply dentate, the teeth
mucronate; upper surface dark green, dull,
sparsely appressed-pubescent, with slightly
prominent venation; lower surface pale green,
sparsely appressed-pubescent, with the reticulate
venation prominent; terminal leaflet 8-16 × 9-19
cm, rhombic, the base cuneate or sub-reniform;
lateral leaflets asymmetrical, broadly ovateelliptical,
the base cuneate-subtruncate; petiolules
thickened, pubescent, with a pair of stipels at the
base; rachis 3-4 cm long, pilose; petioles 8-13 cm
long, sulcate, pilose, with the base broadened.
Inflorescences of axillary pseudoracemes, erect,
30-45 cm long, the flowers in groups of 1-5 per
node of the inflorescence; pedicels 6-8 mm long;
bracteoles minute, oblong. Calyx 9-11 mm long,
green, campanulate, the sepals 4, one larger that
the others; corolla blue or blue-violet, the standard
semicircular, ca. 1.5 cm long, emarginate, the
wings and the keel as long as the standard;
stamens 10, diadelphous. Fruit an oblong legume,
flattened, 7-15 × 1.1-2 cm, pubescent. Seeds
quadrangular, flattened, ca. 7 mm long, dark
brown.
Phenology: Collected in flower during
September and in fruit in January, February, and
August.
Status: Exotic, cultivated and naturalized,
locally common.
Distribution: In areas of degraded vegetation,
along trails and in secondary forests. Native of
southern Mexico, widely cultivated throughout the
tropics for its edible tuberous roots.
Public Forest: Guajataca.
Erect herbs or twining vines, with a pubescence of uncinate hairs. Leaves alternate, trifoliolate,
with the rachis more or less elongate; stipules striate, truncate at the base, persistent; stipels minute.
Inflorescences of axillary racemes, with the nodes not swollen and lacking extrafloral nectaries; bracts