10. Paliurus Miller, Gard. Dict. Abr. ed. 4. vol. 3. 1754.
Christ-thorn [Classical Greek name, perhaps derived from pálin, again or once more, and oúron or oureó, urine or to make water, alluding to diuretic properties of roots and leaves of P. spina-christi] Christ-thorn [Classical Greek name, perhaps derived from pálin, again or once more, and oúron or oureó, urine or to make water, alluding to diuretic properties of roots and leaves of P. spina-christi]
Guy L. Nesom
Shrubs [or trees], sometimes clambering, armed with stipular spines; bud scales present. Leaves deciduous [persistent], alternate; blade not gland-dotted; 3-veined from base (acrodromous), secondary veins distal to basal veins well developed. Inflorescences axillary, cymes; peduncles and pedicels not fleshy in fruit. Pedicels present. Flowers bisexual; hypanthium hemispheric to patelliform, 2–3 mm wide; sepals 5, spreading, pale yellow, deltate, keeled adaxially; petals 5, white, hooded, obovate, clawed; nectary fleshy, filling hypanthium, margin entire or 5-angled; stamens 5; ovary 1/2-inferior, 2–3-locular; styles 2–3, connate proximally. Fruits samaras. x = 12.
Species 5 (1 in the flora): introduced, Texas; Europe, e Asia.
The fruit of Paliurus was described by C. Schirarend and M. N. Olabi (1994) as a dry, indehiscent drupe. The gynoecium base in Paliurus begins to swell laterally following fertilization, forming a persistent, disciform, cupulate, or hemispheric wing of varying thickness (D. O. Burge and S. R. Manchester 2008). This enlarged and winglike receptacle is diagnostic of the genus.
SELECTED REFERENCES Burge, D. O. and S. R. Manchester. 2008. Fruit morphology, fossil history, and biogeography of Paliurus (Rhamnaceae). Int. J. Pl. Sci. 169: 1066–1085. Schirarend, C. and M. N. Olabi. 1994. Revision of the genus Paliurus Tourn. ex Mill. (Rhamnaceae). Bot. Jahrb. Syst. 116: 333–359.