Ruellia Linnaeus 1753
Creators: name: Silva, Marcos José Da
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Lamiales
Acanthaceae
Ruellia

description: Key to Ruellia species with red flowers occurring in Goiás
1. Flowers in lax or congested terminal thyrses; corolla infundibuliform always with curved lobes; bracteoles> 1 cm long, foliaceous, covered with non-glandular and glandular trichomes ........................................................................................................................2
- Flowers usually in compound dichasia or monochasia, both long-pedunculate, solitary, in pairs(or even three), or in fascicles in the leaf axils; corolla bilabiate or tubiform with straight or slightly curved lobes; bracteoles, when present, <5 mm long, with nonglandular trichomes ............................................................................................................................................................................4
2. Plants glabrous; leaves always opposite, scabridulous on both surfaces, trichomes unicellular; thyrses glomeruliform 4-sided; bracts lanceolate, with sessile glandular trichomes on lower surface; bracteoles ovate; flowers subsessile; calyx foliaceous with subequal lobes; cystoliths conspicuous, seeds 7 or 8 ............................................................................ Ruellia scarlatina (Fig. 5, B)
- Plants indumented; leaves opposite and whorled on the same individual, indumented by velutinous or villous and pluricellular trichomes; thyrses elongated; bracts elliptic or elliptic-obovate covered by glandular stipitate trichomes on both surfaces; bracteoles oblanceolate or spatulate; flowers conspicuously pedicellate, calyx with equal lobes; cystoliths inconspicuous; seeds 3 or 4.......... ............................................................................................................................................................................................................3
3. Leaves sessile, elliptic-obovate with apex obtuse, villous and not whitish on both surfaces; secondary veins prominent on abaxial surface, straight; branches densely villous; capsules densely villous ................................................ Ruellia angustior (Fig. 3, F–H)
- Leaves petiolate, broadly elliptic or ovate, with apex shortly acuminate, densely velutinous-whitish on both surfaces; secondary veins impressed on abaxial surface, curved; branches densely velutinous; capsules glabrous or glabrescent .................................... ......................................................................................................................................................... Ruellia adenocalyx (Fig. 3, A–E)
4. Flowers in monochasial or compound dichasia, long pedunculate; seeds 8–16 ................................................................................5
- Flowers solitary, in pairs of (or even three) fascicles, sessile; seeds 4–6 ............................................... Ruellia densa (Fig. 4, C, D)
5. Corolla ventricose, slightly bilabiate, with erect or ascending lobes and yellow throated internally; stamens weakly didynamous; seeds 10–16 ....................................................................................................................................... Ruellia brevifolia (Fig. 4, A, B)
- Corolla not ventricose, conspicuously bilabiate, with lobes conspicuously curved and throat red or orange internally; stamens conspicuously didynamous; seeds 8–12.............................................................................................................................................6
6. Subshrubs erect; leaves indumented, with apex and base obtuse; flowers in monochasia; corolla hypocrateriform, slightly bilabiate; seeds 10–12, uniformly indumented.......................................................................................................... Ruellia elegans (Fig. 5, B)
- Subshrubs with supporting branches; leaves glabrous with apex acuminate and base slightly amplexicaulous; flowers in longpedunculate dichasia; corolla tubular conspicuously bilabiate; seeds 8, indumented on margins.................... Ruellia amplexicaulis
description: Published as part of Silva, Marcos José Da, 2022, Ruellia scarlatina, a new name for the sixty-year-old but misunderstood Ruellia capitata Rizzini (Acanthaceae), pp. 55-65 in Phytotaxa 547 (1) on page 60, DOI: 10.11646/phytotaxa.547.1.5, http://zenodo.org/record/6555939