Dichilanthe, a disjunctly distributed, arborescent Southeast Asiatic genus (D. zeylanica:Sri Lanka;D. borneensis:West Borneo) with collar‐like, persistent stipules, has strongly zygomorphic, ornithophilous flowers which show secondary pollen presentation. The curved corolla is two‐lipped. The upper lip consists of 2, and the lower lip of 3 fused corolla lobes. The calyx, too, is zygomorphic. The curved, exserted style ends in a swollen “stylar head' which apically bears two small stigmatic (receptive) areas in a zygomorphic arrangement. The flowers are borne in compact, terminal heads, held together by enlarged stipules of a bract‐pair immediately below the inflorescence. The dispersal units (diaspores) mimic dipterocarp fruits. They consist of a persistent, wing‐like pair of bracts whose±cuplike stipules enclose the fruits. The diaspores break off at the node immediately below the bract‐pair, where there is a distinct abscission zone. Initial on”primary“dispersal by wind may be followed by facultative”secondary“dispersal by floating in water.”Pith tissue“produced by each fruit of the diaspore, and the air spaces contained therein, are likely to be adaptations to floating. This”pith tissue“, a loose, parenchymatic,± irregularly arranged area of the fruit wall which partially disintegrates during fruit maturation, represents a modified portion of the endocarp; the remainder of the endocarp is”normal“sclerenchymatic tissue coating the two locules. The initial stages of this endocarp differentiation are already observable in early developmental stages, i.e., in ovaries of flower buds and open flowers. The bicarpellate ovaries contain a solitary, anatropous pendulous ovule per locule. Viable seeds have large embryos and only c. 5–6 layers of oily endosperm; their exotesta cells have delicate, ring‐like thickenings. In developing fruits of individual inflorescences, a high frequency of seed abortion was noted. Not uncommonly, there is only a single viable seed per dispersal unit, i.e., only a solitary seedling emerging from a diaspore. Germination of the seeds is cryptocotylar. The pollen ofD. zeylanicais suboblate and 5‐ or 6‐colpate (with the colpi being rather short); the exine is finely reticulate. In spite of several of its character states being unusual and aberrant, the tribal position ofDichilanthein the Guettardeae is not questioned, although it is concluded that the genus occupie
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