Key to species of the genus Hemipogon s. str.

1. Leaves opposite; flowers with short, 3-lobed staminal corona lobes ................................................. .......................................................................................... H. trilobatus Bitencourt & Rapini sp. nov.

– Leaves verticillate or spirally arranged, flowers without corona ...................................................... 2

2. Leaf blade filiform, spirally arranged ............................................................................................... 3

– Leaf blade acicular or ovate to lanceolate, verticillate ..................................................................... 4

3. Corolla lobes 8.5–10 mm long, twisted in the bud, adaxially barbate on the basal half, sericeous on the apical half ....................................................................................... H. irwinii Fontella & Paix „o

– Corolla lobes 3.8–7 mm long, straight in the bud, adaxially barbate on the basal third, puberulous towards the apex .................................................................................................. H. setaceus Decne.

4. Leaves sessile, the blade acicular, ± 1.5 mm wide ....................... H. acerosus var. acerosus Decne.

– Leaves petiolate, the blade ovate to lanceolate, ca 3 mm wide .......................................................... ............................................................................................... H. acerosus var. platyphyllus Hoehne