Inflorescence a raceme or spike with flowers 1–several in bract axils, or flowers solitary; bracts leaf-like or reduced. Flowers zygomorphic to ± actinomorphic, bisexual, 3–5-merous. Calyx tubular and 3–5-lobed or sepals 4 or 5 and ± free; persistent in fruit. Corolla tubular, 2-lipped or ± equally 3–5-lobed, the mouth often restricted by swellings (the palate); tube sometimes extended into a spur at base; usually not persistent in fruit. Stamens epipetalous, usually 4 in pairs of unequal length (didynamous), or 2, with or without a pair of staminodes or rarely stamens 5; anthers 2- or 1-locular, opening by longitudinal slits or almost pores. Ovary superior, 2-carpellate and 2-locular with the septum in the lateral plane; placentation axile or free-central (Limosella); ovules many; style 1, terminal, with a simple or 2-lobed stigma.
Fruit partly or completely enclosed in persistent calyx, either a septicidal and/or loculicidal capsule, splitting usually from the apex, sometimes from the base, or consisting of 2 1-seeded nutlets (cocci).
Many cultivars are grown as garden ornamentals, these include species of Digitalis (foxgloves), Mimulus (monkey-flowers), Antirrhinum (snapdragons). A number of these have escaped from cultivation and become naturalized. The Australian species of Euphrasia cannot be grown in gardens, presumably owing to their semiparasitism. Digitalis is the source of the drug digitalin used in heart medicine. Species of other genera are used in herbal medicine, notably the European Euphrasia in eye treatments, while the Aborigines used Stemodia in the treatments of various ailments.
Note: all measurements are taken from dried specimens; add about 10% to corolla measurements for fresh specimens. Corolla measurements are from the point of insertion to the apex of the upper side; spurs are measured from their apex to the base of the corolla at the level of the ovary. Pedicels and calyces are measured in flowers unless stated otherwise; they frequently elongate as the fruit develops.
**Orthocarpus purpurascens Benth. was recorded from Agricultural Research establishments at Richmond and Trangie before 1920. It does not appear to have become naturalized. This species is a semiparasitic villous erect annual with finely pinnatisect leaves.
| | Key to the family SCROPHULARIACEAE | |
| 1 | Leaves scale-like; stem, leaves, bracts and calyx brown | Orobanche |
| 1* | Leaves conspicuous, not scale-like; stem, leaves, bracts and calyx green | 2 |
| 2 | Bracteoles present between the calyx and bract (minute in Bacopa caroliniana) | 3 |
| 3 | Calyx split down lower side; corolla 15–20 mm long, narrow-campanulate; anthers 2-locular | Centranthera |
| 3* | Calyx equally cleft between the lobes or sepals; corolla 5–12 mm long, 2-lipped, trumpet-shaped, campanulate or cylindrical; anthers 1- or 2-locular | 4 |
| 4 | Sepals fused for more than half their length | 5 |
| 5 | Stem very short, within leafy rosettes connected by rhizomes; inflorescence scape-like; corolla 2-lipped; anthers 1-locular | Mazus |
| 5* | Stem elongated, erect, with spaced leaves; inflorescence a terminal spike; corolla trumpet-shaped; anthers 1-locular | Buchnera |
| 4* | Sepals fused for less than half their length | 6 |
| 6 | Fertile stamens 2, sometimes with staminodes; corolla cylindrical | 7 |
| 7 | Herbs; leaves thin, not densely crowded | Gratiola |
| 7* | Alpine subshrub; leaves leathery, densely crowded | Chionohebe |
| 6* | Fertile stamens 4, staminodes absent or present; corolla 2-lipped or more or less campanulate | 8 |
| 8 | Leaves radical; inflorescence scape-like; sepals partly fused at base; bracteoles alternate, borne on pedicel well below calyx; anther loculi contiguous at apex | Mazus |
| 8* | Leaves cauline; inflorescence terminating leafy branches, solitary or raceme-like; sepals free to very base; bracteoles opposite, just below or appressed to calyx; anther loculi contiguous or separate | 9 |
| 9 | Sepals unequal; corolla more or less campanulate, almost actinomorphic; anther loculi contiguous; capsule loculicidal or also septicidal | Bacopa |
| 9* | Sepals equal; corolla strongly 2-lipped; anther loculi separate; capsule septicidal | Stemodia |
| 2* | Bracteoles absent | 10 |
| 10 | Sepals fused for less than half their length | 11 |
| 11 | Stamens 2; calyx and corolla 4- or 5-, rarely 6-merous, the corolla almost equally lobed or 2-lipped and lower lip slipper-shaped | 12 |
| 12 | Corolla almost equally lobed; | 13 |
| 13 | Capsule septicidal and often partly loculicidal, usually not strongly compressed; woody perennials or subshrubs | Derwentia |
| 13* | Capsule loculicidal and sometimes partly septicidal, usually strongly laterally flattened; annual or perennial herbs or semiwoody perennials | 14 |
| 14 | Perennial herbs, rarely stout; leaves various | Veronica |
| 14* | Semiwoody perennials; leaves broad-ovate and toothed | Parahebe |
| 12* | Corolla slipper-shaped, the lower lip greatly recurved above and much larger than upper; anthers 1-locular, with staminodes absent | Calceolaria |
| 11* | Stamens 5 or 4; calyx and corolla 5-merous, the corolla usually unequally lobed | 15 |
| 15 | Leaves opposite or whorled | 16 |
| 16 | Corolla tube swollen or pouched at base; capsule asymmetrical in side view | 17 |
| 17 | Corolla tube long, not pouched, 2 upper lobes pointed outwards and 3 lower lobes | Misopates |
| 17* | Corolla tube pouched, lower lip entire or emarginate, upper lip 4-lobed | Nemesia |
| 16* | Corolla tube symmetrical at base; capsule symmetrical in sides view | 18 |
| 18 | Corolla subglobose, with a short tube and 5 small lobes; staminode present, scale-like; inflorescence many-flowered, a panicle of cymes | Scrophularia |
| 18* | Corolla 2-lipped, with a long or short tube; staminode absent; inflorescence few-flowered, a raceme | 19 |
| 19 | Branches prominently 4-ribbed; sepals broad, imbricate; corolla more than 20 mm long | Artanema |
| 19* | Branches obscurely to distinctly 4-angled; sepals narrow, hardly overlapping; corolla less than 10 mm long | Lindernia |
| 15* | Leaves alternate, at least in upper parts | 20 |
| 20 | Corolla closed at mouth by palate on lower side, the base of the tube spurred on lower side | 21 |
| 21 | Leaves with lamina reniform to semicircular, lobed with 5–9 rounded to triangular lobes, palmately veined; capsules dehiscing by irregular longitudinal apical slits | Cymbalaria |
| 21* | Leaves with lamina entire or with a pair of large basal lobes, pinnately veined; capsules dehiscing by an apical pore or irregular longitudinal slits | 22 |
| 22 | Plants erect; leaves sessile; flowers in terminal racemes or spikes; capsules dehiscing by irregular longitudinal slits | Linaria |
| 22* | Plants procumbent to ascending; leaves petiolate; flowers solitary; capsules dehiscing by an apical pore covered by a detachable lid | Kickxia |
| 20* | Corolla mouth open, with or without palate, the tube symmetrical at base | 23 |
| 23 | Corolla rotate, less than 15 mm long, tube much shorter than the 5 widely spreading lobes; stamens 5 or 4 and sometimes with a staminode; anthers 1-locular, upper 2 or 3 reniform, the lower decurrent along filaments | Verbascum |
| 23* | Corolla 2-lipped, more than 30 mm long, the tube longer than the lobes; stamens 4, sometimes with a staminode; anthers 2-locular, reniform | 24 |
| 24 | Erect herbs; leaves with lamina attenuate at base; capsule septicidal; seeds not winged | Digitalis |
| 24* | Climbers; leaves with lamina cordate at base; capsule irregularly dehiscing by transverse slit or pore; seeds broadly winged | 25 |
| 25 | Leaves glabrous; sepals less than 10 mm long, lanceolate, apex long-acuminate; seeds not winged | Maurandya |
| 25* | Leaves more or less villous; sepals more than 20 mm long, more or less ovate, apex obtuse or subacute; seeds winged | Lophospermum |
| 10* | Sepals fused for at least half their length | 26 |
| 26 | Leaves densely clustered, their attachment obscure | 27 |
| 27 | Calyx smooth, 3- or 4-lobed; stamens 2 or 4; stigma a broad flap; capsule loculicidal | Glossostigma |
| 27* | Calyx 5-angled, 5-lobed, in depauperate plants rarely 3-lobed; stamens 4; stigma capitate; capsule septifragal (the septum remaining attached to the placental column) | Limosella |
| 26* | Leaves spaced along branches | 28 |
| 28 | Leaves alternate, at least in the upper parts | 29 |
| 29 | Semiaquatic herb, sometimes stoloniferous, with radical leaves entire; flowers solitary; calyx 5-toothed, in depauperate plants rarely less; corolla campanulate, more or less rotate; capsule septifragal | Limosella |
| 29* | Terrestrial herb, non-clonal, with cauline leaves toothed; flowers in racemes; calyx 4-toothed; corolla 2-lipped; capsule loculicidal | Orthocarpus |
| 28* | Leaves opposite or whorled | 31 |
| 31 | Leaves with patches of sessile glands below; calyx equally 4-toothed; anther loculi 2; stigma capitate or obscurely obliquely 2-lobed; capsule loculicidal | 32 |
| 32 | Upper corolla lobes recurved; awns of rearmost pair of anthers longer than the other 6 awns; seeds longitudinally ribbed, scalariform between | Euphrasia |
| 32* | Upper corolla lobes pointed outwards; awns of anthers equal; seeds smooth, finely reticulate or ribbed | 33 |
| 33 | Capsules oblong; seeds smooth or finely reticulate, c. 0.5 mm long | Parentucellia |
| 33* | Capsules globose; seeds ribbed, scalariform between ribs, c. 0.7 mm long | Bartsia |
| 31* | Leaves sometimes with scattered sessile glands; calyx equally 5-toothed or unequally 3- or 4-toothed; anther loculi 2 or 1; stigmas either 2 or 1, flap-like, or 2 | 34 |
| 34 | Calyx smooth, unequally 3- or 4-lobed; anthers 1-locular; capsules septicidal; mat-forming herbs | Glossostigma |
| 34* | Calyx 5-ribbed, equally 5-lobed; anthers 1- or 2-locular; capsules septicidal or irregularly loculicidal; erect or mat-forming herbs | 35 |
| 35 | Stamens 4; anthers 2-locular; stigma 2-flapped (the flaps often appressed); capsule septicidal; erect or prostrate herbs | Mimulus |
| 35* | Stamens 2; anthers 1-locular; mat-forming herbs | 36 |
| 36 | Stigma 1-flapped; capsule tardily and irregularly septicidally and loculicidally from the base | Peplidium |
| 36* | Stigma of 2 terete lobes; capsule septicidal from the apex | Elacholoma |
