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Pachyrhizus erosus

(L.) Urb. (1905)

This name is accepted

Kingdom: Viridiplantae Phylum: Magnoliophyta Class/Clade: Eudicot-Rosids Order: Fabales Family: Fabaceae Genus: Pachyrhizus

chopsui potato, jicama, Mexican turnip, Mexican yam, yam bean

Description

Key Characters:

Growth Form: Climbing or trailing herbs, usually with an often lobed, turnip–shaped tuber up to 30 cm in diameter.

Stems: Stems up to 6 m long, pubescent.

Roots: Roots tuberous.

Leaves: Leaves compound. Alternate. Leaflets broadly ovate or broadly rhombic, 3–18 cm long, 4–20 cm wide. Margins irregularly toothed. Veins ending at leaf margins, the margins apiculate at the endpoint of each vein. Petiolate. Stipules lanceolate. Leaflets stipellate.

Flowers: Flowers in pseudoracemes up to 70 cm long, in clusters on a short, warty, lateral axis, these in long pseudoracemes, bracts and bracteoles small, setaceous, caducous. Flowers papilionaceous. Calyx lobes 5, the upper 2 lobes connate into a larger bifid lobe. Corolla blue, bluish mauve, or pale purple, standard with a green central patch, 1.5–2 cm long, standard obovate, with a transverse ridge inside at base, with inflexed auricles, wing petals retrorsely appendaged, keel petals incurved, obtuse. Stamens 10; upper stamen distinct, the other 9 connate into a tube. Ovary superior; style 1, apical, dorsoventrally flattened, broadened toward apex, with a row of antrorse hairs on the upper (adaxial) side extending up from the ovary; stigma subglobose, lateral.

Fruit: Pods straight or curved; 7.5–14 cm long; 1–1.8 cm wide; dehiscent; linear–oblong; compressed; thickened around the seeds; with transverse impressions between each seed. Seeds 4–12; pale brown to purplish black; ellipsoid or rounded; 8–10 mm long; 7–10 mm wide; hilum small.

Ploidy: 2n = 20; 22

Habitat:

Elevation Range: ca. 260 m.

Historical Distribution

Uses and Culture

USES

  • Yes

Natural History

Statewide Status

Naturalized

Island Status

Kaua'i Only found in cultivation
O'ahu Only found in cultivation
Molokai Only found in cultivation
Hawai'i Naturalized

Dispersal Agents


Pollinators

Notes

  • 260 m
  • Description digitized by Yuki Ishida
  • Description digitized from the Manual of the Flowering Plants of Hawaii
  • Hawaii made in 1974

Bibliography

Name Published In: Symb. Antill. 4: 311 (1905)

Other References

Wagner et al. 1990:689 (H); Staples & Herbst 2005:299 (KEY), 319 (DESCR); Herbst 5052 BISH (H†, 1974)

Occurrences

SNo. Scientific Name Locality Habitat Basis of Record Description Recorded By Record Number Island Source Date
1 Pachyrhizus erosus Honolulu. Salt lake Area Preserved_Specimen Flowers purple, fruits green, not ripe. Obata, J.K. Oahu BISH 1994-10-21
2 Pachyrhizus erosus East end of Molokai, mi 19; open valley floor. Residence of Mr. & Mrs. George Peabody Preserved_Specimen Vine Stem green and tan. Leaves dark green. Flowers purple in upright clusters, pealike. Root tan to light brown, large, flat round; flesh white, crisp. Seeds poisonous. Edible root, eaten raw or cooked. Evans, M. 17 Molokai BISH 1990-06-30
3 Pachyrhizus erosus Resience of Mr. and Mrs. Peabody. East end of Molokai. mile 19, open valley floor, sunny coast Preserved_Specimen Vine Stem green and tan. Leaves dark green. Flowers purple in upright clusters, pealike. Root tan to light brown, large, flat round; flesh white, crisp. Seeds poisonous. Edible root, eaten raw or cooked. Evans, M. 17 Molokai BISH 1990-06-30
4 Pachyrhizus erosus East end of Molokai, mi 19; open valley floor. Residence of Mr. & Mrs. George Peabody Preserved_Specimen Vine Stem green and tan. Leaves dark green. Flowers purple in upright clusters, pealike. Root tan to light brown, large, flat round; flesh white, crisp. Seeds poisonous. Edible root, eaten raw or cooked. Evans, M. 17 Molokai BISH 1990-06-30
5 Pachyrhizus erosus Hookena Preserved_Specimen Vine with white flowers Herbst, D.R. 5052 Hawaii BISH 1974-10-07
6 Pachyrhizus erosus Moanalua Preserved_Specimen Obata, J.K. Oahu BISH 1985-09-09
7 Pachyrhizus erosus Honolulu Preserved_Specimen Obata, J.K. Oahu BISH 1986-10-20
8 Pachyrhizus erosus Honolulu. Salt lake Area Preserved_Specimen Obata, J.K. Oahu BISH 1994-10-21
9 Pachyrhizus erosus Moanalua Preserved_Specimen Obata, J.K. Oahu BISH 1985-09-09
10 Pachyrhizus erosus Puhi Camp just west of kauai community college Preserved_Specimen Flynn, T.W. 2013 Kauai BISH 1986-12-05
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