Prostrate, erect or rarely, climbing, herbs or shrubs, or rarely small trees. Branches decussate, frequently angled, more rarely terete, often with transverse ridges across the node. Leaves opposite, subopposite or whorled (Crossandra), exstipulate, simple, usually with cystoliths (intercellular concretions, usually of calcium carbonate, which appear as white streaks on the upper surface), but lacking in Aphelandra, Gynocraterium, Nelsonia, Staurogyne, and Thunbergia, margins entire, crenate or undulate. Inflorescences axillary and/or terminal, flowers solitary or arranged in spikes, cymes or racemes, often densely clustered, frequently in axils of conspicuous bracts and with 2 bracteoles; bracts often leaf-like, sometimes enclosing corolla tube. Flowers zygomorphic to nearly actinomorphic, bisexual; calyx synsepalous at least basally, persistent, lobes 4 or 5, rarely (Thunbergia) an entire ring, or 12-20-lobed; corolla sympetalous, the limb 5-lobed or 2-lipped (rarely 1-lipped),lobes imbricate or contorted in bud, basally usually divided into a distinct narrow tube and wider throat; stamens 4, usually didynamous, or 2 fertile and sometimes accompanied by 1 or 2 staminodes, adnate to corolla tube, filaments free or basally connate in pairs, anther thecae usually 1 or 2, usually parallel, rarely divergent or transverse, muticous (without a projection), obtuse or rounded, or basally spurred, longitudinally dehiscent; pollen very varied in structure, striation and reticulation; disk annular and nectar-producing at base of ovary; ovary superior, 2-locular, either with 2 collateral (Thunbergia) or more commonly 2-10 superposed ovules per locule; placenta axile; style filiform, simple, stigma entire or more commonly 2-lobed, one lobe frequently smaller than the other. Fruits loculicidal, 2-valved capsules, frequently explosively dehiscent either on drying or on wetting, seeds usually borne on hook-like retinacula (funicles), these persistent in valves after seeds have been discharged or retinacula lacking (Gynocraterium, Staurogyne, Thunbergia); seeds 2-many, usually flattened, sometimes spheroidal (Gynocraterium, Staurogyne), testa smooth or roughened, sometimes with mucilaginous trichomes which expand when moistened.
Guianas: present Pantropical: present pansubtropical: present temperate zones of both hemispheres: present
Pantropical and pansubtropical, sparingly distributed in temperate zones of both hemispheres; about 2500 species in about 250 genera; in the Guianas 83 species in 24 genera.
Besleria surinamensis Miq. Crossandra undulifolia Salisb. Dipteracanthus canescens Nees Dipteracanthus humilis Nees var. diffusus Nees Dipteracanthus vindex Nees Hygrophila conferta Nees Leptostachya parviflora Nees Leptostachya martiana Nees var. hispida Nees Ruellia blechum L. Staurogyne stolonifera (Nees) Kuntze Thunbergia alata Bojer ex Sims Thunbergia fragrans Roxb. Justicia potarensis (Bremek.) Wassh. Lepidagathis cataractae (Nees) Wassh. Polylychnis radicans (Nees) Wassh. Arrhostoxylon rubrum (Aubl.) Nees var. attenuatumto Ruellia rubra Aubl. Arrhostoxylon rubrum (Aubl.) Nees var. glomeruliflorum Bremek.to Ruellia rubra Aubl. Arrhostoxylon rubrum (Aubl.) Nees var. multiflorum Bremek.to Ruellia rubra Aubl. Arrhostoxylon rubrum (Aubl.) Nees var. parviflorum Bremek.to Ruellia rubra Aubl. Arrhostoxylon rubrum (Aubl.) Nees var. pygmaeum Bremek.to Ruellia rubra Aubl. Justicia cayennensis (Nees) Lindau var. parvifolia Bremek.to J. cayennensis (Nees) Lindau Justicia martiana (Nees) Lindauto J. comata (L.) Lam. Justicia parviflora (Nees) Lindauto J. comata (L.) Lam. Justicia schomburgkiana (Nees) V.A.W. Grahamto J. sphaerosperma Vahl Lepidagathis surinamensis (Bremek.) Wassh.to L. cataractae (Nees) Wassh. Polylychnis essequibensis Bremek.to P. radicans (Nees) Wassh. Ruellia pipericaulis Rizzinito R. inflata Rich. Ruellia radicans (Nees) Lindauto Polylychnis radicans (Nees) Wassh. Ruellia ventricosa Poir.to R. inflata Rich. Sericographis palustris Neesto Justicia laevilinguis (Nees) Lindau Staurogyne linearifolia Bremek.to S. stolonifera (Nees) Kuntze Stephanophysum cordifolium Mart. ex Neesto Ruellia inflata Rich. Teliostachya coppenamensis Bremek.to Lepidagathis cataractae (Nees) Wassh.
In this predominantly herbaceous family
Growth rings absent or inconspicuous.
Vessels mostly in radial multiples of 2-4, occasionally more, in diffuse or more or less radial arrangement. Few in
Rays 1-4-seriate or exclusively uniseriate (
Parenchyma almost absent, restricted to a few strands bordering a vessel. Strands often 2-3-celled, up to 6; also undivided, fusiform cells present.
Ground tissue in most genera septate fibres, thin-walled with a wide lumen, in