Hornschuchia Nees
Creators: name: Vilela, Lucas
name: Lopes, Jenifer De Carvalho
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Magnoliales
Annonaceae
Hornschuchia

description: Genus Hornschuchia Nees
Flora 4 (1): 302 (Nees 1821). − Type species: Hornschuchia bryotrophe Nees.
Mosenodendron R.E.Fr., Kongliga Svenska Vetenskaps Akademiens Handlingar, ser. 3 34 (5): 8 (Fries 1900). – Type species: Mosenodendron insigne R.E.Fr.
Description
Trees to shrubs. Leaves chartaceous to coriaceous with primary vein impressed adaxially. Inflorescence 1-flowered or 2–22-flowered; axillary, supra-axillary, terminal or cauliflorous, i.e., ramiflory, trunciflory, flagelliflory. Flowers white, rarely pinkish, trimerous; three sepals and six petals in two whorls; calyx with sepals completely connate, rarely connate at the base; corolla with linear petals; stamens 3–18; carpels 2–9. Fruit with 1–5 monocarps, monocarps obovate, globose, ellipsoid, obloid, fusiform; stipe 1.5–9 mm long, subsessile to sessile. Seed 1–8, globose, obovoid, obloid-ellipsoid, ellipsoid, flattened-ellipsoid, with aril, rarely without aril.
Hornschuchia is recognized by its small and white flowers, with linear petals and cupuliform calyx. It is similar to Trigynaea and Bocagea; however, the petals in these two genera are ovate, elliptic or lanceolate (Johnson & Murray 1995).
Key to the species of Hornschuchia Nees
1. Leaves with commissural veins evident ............................................................. H. bryotrophe Nees
− Leaves without commissural veins ................................................................................................... 2
2. Inflorescence axillary, supra-axillary to terminal or ramiflorous ...................................................... 3
− Cauliflorous, except ramiflorous ......................................................................................................11
3. Inflorescence 1-flowered ................................................................................................................... 4
− Inflorescence 2–22-flowered ........................................................................................................... 10
4. Calyx connate at the base with triangular apex ....................................... H. citriodora D.M.Johnson
− Calyx completely connate (cupuliform) with truncate apex ............................................................. 5
5. Calyx 3–8 mm long .......................................................................................................................... 6
− Calyx 1–2(–3) mm long .................................................................................................................... 8
6. Stamens 10, 4 mm long, carpels 5.5 mm long. Monocarp obloid with acute apex, 20–24 × 9–12 mm, stipe 1–2 mm long .................................................................... H. mellosilvae L.Vilela & J.C.Lopes
− Stamens 3–6, 2–3 mm long, carpels 2–3 mm long. Monocarp globose to ellipsoid with rounded apex, 8–13 × 5–9 mm, sessile .................................................................................................................... 7
7. Floral bud cylindrical with obtuse apex. Fruit 1 monocarp with persistent calyx .............................. .................................................................................................................. H. lianarum D.M.Johnson
− Floral bud globose to ovoid to conical with acute apex. Fruit 2–5 monocarps with caducous calyx ... .................................................................................... H. mediterranea Mello-Silva & D.M.Johnson
8. Calyx glabrescent. Monocarp sessile ................................................................... H. polyantha Maas
− Calyx densely covered in trichomes. Monocarp stipe 1.5–3 mm long ............................................. 9
9. Leaves narrowly elliptic to elliptic, oblanceolate to narrowly oblong, obovate or rarely lanceolate. Pedicel 7–37 mm long ............................................................................................ H. myrtillus Nees
− Leaves narrowly ovate to ovate or lanceolate. Pedicel 1–7 mm long ..... H. alba (A.St.-Hil.) R.E.Fr.
10. Floral bud cylindrical. Monocarp fusiform, 5–8 mm wide, densely covered in trichomes, whitish in vivo ........................................................................................................... H. obliqua Maas & Setten
− Floral bud conical. Monocarp globose, 16–19 mm wide, glabrous, green in vivo ............................ ..................................................................................................................... H. santosii D.M.Johnson
11. Trunciflory ...................................................................................................................................... 12
− Flagelliflory, i.e., inflorescence branches 4.5–100 cm long, emerging from the basal part of the trunk and running near the soil ................................................................................................................. 13
12. Inflorescence branches 6–19 cm long ...................................................... H. leptandra D.M.Johnson
− Inflorescence emerging close to the trunk ............................................. H. cauliflora Maas & Setten
13. Calyx glabrescent. Bracts caducous .................................................................... H. polyantha Maas
− Calyx densely covered in trichomes. Bracts persistent .......................................... H. myrtillus Nees
description: Published as part of Vilela, Lucas & Lopes, Jenifer De Carvalho, 2022, Hornschuchia (Annonaceae), an endemic and threatened genus from the Brazilian Atlantic Forest, pp. 75-108 in European Journal of Taxonomy 828 on pages 77-78, DOI: 10.5852/ejt.2022.828.1859, http://zenodo.org/record/6823766