Rudgea Salisbury 1807
Creators: name: Lachenaud, Olivier
name: Bruniera, Carla P.
name: Zappi, Daniela C.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Rubiaceae
Rudgea

description: Key to the species
1. Leaves ternate; stipular appendages all dorsal and shorter than sheath (Fig. 1B) (Guyana, Venezuela, N. Brazil, Peru) ................... .................................................................................................................................................................................. R. coussareoides
- Leaves opposite; stipular appendages exceeding sheath, except in R. bolivarensis ...........................................................................2
2. Stipules narrowly tubular with sheath longer than broad (but often splitting very early at flower-bearing nodes); inflorescences glabrous, sometimes with large foliaceous bracts; corolla lobes corniculate, glabrous outside ........................................................3
- Stipules with sheath broader than long; inflorescences puberulous (rarely glabrous in R. maypurensis), never with large foliaceous bracts; corolla lobes not corniculate, or, if corniculate, pubescent or puberulous outside at least near the apex ..............................4
3. Stipules with dorsal appendages inserted near the base; inflorescence subcapitate with large foliaceous imbricate bracts 10–20 x 2–7 mm; corolla tube 13 mm long (French Guiana) ......................................................................................................... R. pungens
- Stipules with dorsal appendages inserted in upper half; inflorescence distinctly branched with small subulate bracts 3–5 mm long; corolla tube 6 mm long (French Guiana: Kaw Mountain) ................................................................................................ R. billietiae
4. Stipules ± truncate with appendages shorter than sheath (Fig. 1A); leaves thickly coriaceous, with conspicuously reticulate tertiary venation; corolla lobes glabrous outside and not corniculate (Venezuela, Guyana, N Brazil) ................................... R. bolivarensis
- Stipules with appendages exceeding sheath; leaves with tertiary venation usually rather obscure; corolla lobes corniculate except in R. maypurensis ...............................................................................................................................................................................5
5. Stipules with dorsal appendages recurved, free at base or shortly connate into a keel (Fig. 1E); leaves slightly cordate to rounded at base; corolla lobes not corniculate; pyrenes dorsally verrucose (Venezuela, N Brazil,?SE Colombia)................ R. maypurensis
- Stipules with appendages all erect, the dorsal ones connate into a keel (Fig. 1C–D & F); leaves cuneate to obtuse at base, never cordate; corolla lobes corniculate; pyrenes not verrucose dorsally....................................................................................................6
6. Calyx lobes 3–5 mm long, linear (Fig. 2F); bracts 5–7 mm long, linear to narrowly lanceolate; corolla lobes usually with linear appendages (rarely these short and blunt); fruits ellipsoid to globose; leaf blade with secondary veins weakly ascending (Guyana)...................................................................................................................................................................... R. tanaosepala
- Calyx lobes 0.7–2 mm long, semicircular to subulate (Fig. 2 C-D); bracts usually <3 mm long, or if longer (to 10 mm in R. hostmanniana) then relatively broad; corolla lobes with short and blunt appendages; fruits obovoid, rarely subglobose; leaf blade with secondary veins usually strongly ascending...............................................................................................................................7
7. Stipules with central keel much exceeding the lateral appendages (Fig. 1D); leaves acute (rarely obtuse) at base, with petiole 0.5–2 cm long; inflorescence pyramidal or rarely hemispherical; calyx lobes triangular to semicircular (Fig. 2D); corolla tube 3–5 mm long (widespread) .................................................................................................................................................... R. hostmanniana
- Stipules with central keel roughly equalling the lateral appendages (Fig. 1C); leaves obtuse at base, with petiole 0.2–0.8 cm long; inflorescence hemispherical; calyx lobes subulate to narrowly triangular (Fig. 2C); corolla tube 5–7 mm long (Guyana, Suriname) ........................................................................................................................................................................ R. cornigera
description: Published as part of Lachenaud, Olivier, Bruniera, Carla P. & Zappi, Daniela C., 2022, The Rudgea hostmanniana complex (Rubiaceae) in the Guiana Shield region, pp. 219-242 in Phytotaxa 561 (3) on pages 222-223, DOI: 10.11646/phytotaxa.561.3.1, http://zenodo.org/record/7069870