Identification key for Siparuna species (Siparunaceae) occurring in Ceará

1. Leaves denticulate, serrate or crenate; staminate flowers with trichomes in tufts; floral roof conical, glabrous; floral cup globose; stylar aril present........................................................1.1. Siparuna brasiliensis

1’. Leaves entire, staminate flowers with stellate-lepidote trichomes; floral roof infundibuliform, tomentose; floral cup cupuliform; stylar aril absent .....................................................................1.2. Siparuna guianensis

Taxonomic treatment

Siparunaceae.

1. Siparuna Aublet, Hist. Pl. Guiane: 864. 1775. Type species: Siparuna guianensis Aublet.

Trees or treelets, occasionally decumbent, 1–20(–40) meters high, strongly odoriferous, glabrous or densely hairy with simple, stellate, lepidote, or scale-shaped trichomes. Leaves opposite, occasionally whorled, petiolate, membranous, cartaceous or leathery, entire, serrate, denticulate or crenate. Inflorescence cymose, axillary or cauliflower, with bracts generally small, deciduous or absent. Flowers radial, small, green, yellowish, white or reddish. Floral cup subglobose to cupuliform, enclosing the carpels and stamens. Tepals 4–8, generally persistent, free or united in a ring, rarely forming a calyptra. Floral roof covering the central part of the floral cup. Staminate flowers with 1 to 10(–70) free stamens, rarely fused laterally. Filament flattened, anther with valvate dehiscence, apical. Pistillate flowers with 1 to 35 carpels separated by septa, ovule anatropous. Fruit multiple, cupuliform, globose, subglobose, pyriform or ovoid, with a smooth, warty or tuberculate surface; when mature, purplish, reddish or yellowish, often crowned by tepals and traces of the floral roof, with drupelets enclosed until maturity, or more rarely, the receptacle does not open. Drupelets (usually called “seeds” by non-specialists) elliptical to globose, with a thin, transparent, shiny epicarp, fleshy, whitish-gray, bluish, yellowish or pinkish exo- and mesocarp, and hard, endocarp verrucular, sometimes with a red or yellow stylar aril (superaryl), single seed (Renner & Hausner 2005; Peixoto et al. 2020; Brunassi et al. 2022).