5. EXBUCKLANDIA R. W. Brown, J. Wash. Acad. Sci. 36: 348. 1946.
马蹄荷属 ma ti he shu
Bucklandia R. Brown ex Griffith, Asiat. Res. 19(1): 94. 1836, not Presl (1825), nor Brongniart (1828); Symingtonia Steenis.
Trees, evergreen; branchlets stout, with distinct nodes. Leaves alternate, long petiolate; stipules large, leathery, coherent, caducous, leaving annular scar at each node; leaf blade simple or, in saplings and young shoots, palmately 3–5-lobed, thickly leathery, margin entire, venation palmate. Inflorescence capitate, sometimes in compound racemes, usually axillary, pedunculate, 7–16-flowered. Flowers bisexual, initially enclosed by a pair of stipules. Floral cup adnate to ovary base. Petals absent or 2–5, white, linear, straight in bud. Stamens 10–15; filaments varying in length, subulate; anthers oblong or ovoid, thecae 1-sporangiate, each dehiscing by 1 valve, connective apiculate. Ovary semi-inferior; ovules 5 or 6 per locule; styles somewhat elongated; stigmas decurrent, caducous in fruit. Infructescences globose or subglobose. Capsules dehiscing loculicidally by 4 valves; exocarp usually smooth, sometimes tuberculate. Seeds 5–7 in each locule, upper 4 or 5 sterile and wingless, lower 1 or 2 fertile and narrowly winged, embryo scant, fleshy; cotyledon compressed. 2n = 32.
About four species: Bhutan, China, India, Indonesia, Laos, Malaysia, Myanmar, Nepal, Sikkim, Thailand, Vietnam; three species (one endemic) in China.
Some authors have questioned the validity of Exbucklandia because Brown did not give the place of publication of the replaced synonym, Bucklandia. However, the rule requiring citation of this information (St. Louis Code, Art. 33.3) applies only to names published on or after 1 January 1953.