银杏科 yin xing ke
Authors: Liguo Fu, Nan Li & Robert R. Mill
Trees deciduous, dioecious; trunk tall, densely branched; branchlets dimorphic: both long and short. Leaves sparsely and spirally arranged on long branchlets, fasciculate on short branchlets, long petiolate, flabellate, venation parallel, close, dichotomous, open but with rare anastomoses, base broadly cuneate, margin straight, entire, apex 2-lobed or notched. Reproductive structures produced in clusters in axils of scalelike leaves at apex of short branchlets before leaves expand. Pollen cones pedunculate, pendulous, catkinlike; microsporophylls numerous, spirally and rather sparsely arranged; microsporangia 2, elliptic; pollen sacs longitudinally dehiscent. Ovules borne on a long, dichotomously branched peduncle sometimes dividing into 3-5 terminal forks; each fork discoid at apex, bearing an erect, sessile ovule; usually only 1 seed ripening per peduncle. Seeds long pedunculate, pendulous, drupelike, with a single integument differentiated into a fleshy, succulent sarcotesta, a bony sclerotesta, and a membranous endotesta; female gametophyte tissue abundant. Cotyledons 2(or 3). Germination hypogeal. 2n = 24*.
* One genus and one species: China.
Cheng Wan-chün & Fu Li-kuo. 1978. Ginkgoaceae. In: Cheng Wan-chün & Fu Li-kuo, eds., Fl. Reipubl. Popularis Sin. 7: 18-23.