Heavily armed monoecious pinnate-leaved palms, usually with tall erect single trunk but sometimes soboliferous and infrequently the caudex not developing into a bole (plant more or less acaulescent): leaves usually long, conspicuously ascend-ing and overarching, irregularly and unequally pinnate, the pinnae frequently aggregate or clustered on the rachis: spadices interfoliar but lowest leaves some-times falling before the fruits mature, consisting-of a stout spiniferous peduncle that extends as an-axis or rachis from the. sides of which many usually simple short branches or rachillae extend, spadix at first inclosed in a long scarcely woody armed cymba-like spathe of 2 valves but which after anthesis is likely to hang as a dead member on a long peduncle and much longer than broad: flowers borne usually on the rachillae, the few pistillates at base and the numerous staminates compactly occupying the upper part, but sometimes the main rachis also bearing pistillate flowers on its upper part; staminate flowers 4-10 mm. long at anthesis, with small calyx and much longer more or less tubular or gamopetalous corolla with valvate lobes, 6 exserted stamens with long versatile or erect anthers, mninute pistillode sometimes present; pistillate flowers much larger, 12 or more mm. long, conic,-envelopes usually connate; ovary 3-loculed: fruit a drupe-like body but mesocarp soon becoming dry or disappearing or remaining in fibrous elements, 3-8 cm. long, ovoid, obovoid or subglobose, variously beaked, smooth, asperulate or aculeate, 1-to 2-seeded, retaining the accrescent floral cup; nutlet with 3 often ornamented or radiate pores, albumen homogeneous, very hard, cavitous in center, raphe much branched.