Sophora is a genus of about 45 species of small trees and shrubs in the pea family Fabaceae. The species have a pantropical distribution. The generic name is derived from sophera, an Arabic name for a pea-flowered tree. The genus formerly had a broader interpretation including many other species now treated in other genera, notably Styphnolobium (pagoda tree genus), which differs in lacking nitrogen fixing bacteria (rhizobia) on the roots, and Dermatophyllum (the mescalbeans). Styphnolobium has galactomannans as seed polysaccharide reserve, in contrast Sophora contains arabinogalactans, and Dermatophyllum amylose. The New Zealand Sophora species are known as kowhai. The seeds of species such as Sophora affinis and Sophora chrysophylla are reported to be poisonous. Fossil record One Sophora fossil seed pod from the middle Eocene epoch has been described from the Miller clay pit in Henry County, Tennessee, United States. Species Sophora comprises the following species: Sophora albescens Sophora albo-petiolulata Sophora alopecuroides —sophora root Sophora bakeri Sophora benthamii Sophora brachygyna Sophora cassioides —Pelú (Chile) Sophora chathamica —coastal kowhai (New Zealand) Sophora chrysophylla —Māmane (Hawaii) Sophora davidii Sophora denudata Sophora dunnii Sophora exigua Sophora fernandeziana (Juan Fernández Islands) var. fernandeziana var. reedeana Sophora flavescens —ku shen (Eastern Asia) var. flavescens var. galegoides var. kronei Sophora franchetiana Sophora fraseri Sophora fulvida —Waitakere kowhai (New Zealand) Sophora godleyi—Godley kowhai, papa kowhai (New Zealand) Sophora howinsula —lignum vitae, Lord Howe kowhai Sophora inhambanensis Sophora interrupta Sophora jaubertii Sophora koreensis – Korean necklace pod Sophora lanaiensis Sophora leachiana Sophora linearifolia Sophora longicarinata —limestone kowhai (New Zealand) Sophora longipes Sophora macrocarpa —mayo or mayú (Chile) Sophora mangarevaensis (French Polynesia) Sophora masafuerana (Juan Fernández Islands) Sophora microcarpa Sophora microphylla —small-leaved kowhai (New Zealand) Sophora molloyi—Cook Strait Kowhai (New Zealand) Sophora mollis subsp. griffithii subsp. mollis Sophora moorcroftiana Sophora nuttalliana Sophora pachycarpa Sophora polyphylla Sophora praetorulosa Sophora prazeri var. mairei var. prazeri Sophora prostrata —dwarf kowhai, prostrate kowhai (New Zealand) Sophora raivavaeensis (French Polynesia) Sophora rapaensis (French Polynesia) Sophora rhynchocarpa Sophora saxicola (Jamaica) Sophora secundiflora, a popular landscape plant, was reclassified to Dermatophyllum secundiflorum. Sophora stenophylla Sophora tetraptera —large-leaved kowhai, Taupo kowhai (New Zealand) Sophora tomentosa —necklace pod (Pantropical on coasts) subsp. littoralis subsp. occidentalis subsp. tomentosa Sophora tonkinensis Sophora toromiro —toromiro (Easter Island) Sophora unifoliata Sophora velutina subsp. cavaleriei subsp. velutina subsp. zimbabweensis Sophora violacea Sophora wightii (India) Sophora xanthoantha Sophora yunnanensis Sophora zeylanica Species names with uncertain taxonomic status The status of the following species is