Amaranthus spinosus L.
Locally known as ‘uray’ (Tagalog), ‘kolitis’ (Bisaya), and spiny amaranth, pigweed (English). It is both wind and insect-pollinated. It flowers from June to January.
An erect shrub with many sharp thorns on its oblique branches and cluster of flowers. Leaves have long petioles, shape is ovate-lanceolate with pointed tips, margin is wavy . Flowers in cluster, axillary or terminal panicles, each panicle consists of dense male or female spikes, each flower cluster is supported by spines (metamorphosed bracts); each floret 5-merous (5 tepals, one tepal with long spine, and 5 stamens), stamen is dorsifixed, dorsiventral; ovary is short, styles three, recurved when mature. Seed is an utricle and ellipsoid, when ripe splits a little below middle; color is shining black to brownish black.
Pollen grain is simple, pantoporate (pores distributed all over the surface) with pores as many as 40 in number, covered by membrane with many small spines. Exine has small perforations and small spines.