General description:- Perennial (rarely annual) herbs without chlorophyll, parasitic on the roots of other phanerogamic plants (usually herbaceous dicotyledons).
Stems:- Erect, usually simple.
Leaves:- Alternate, scale-like, often succulent at first.
Flowers:- In a terminal spike or raceme, rarely in a panicle or solitary. Calyx tubular, cup-shaped or 2-lipped. Corolla 5-lobed, 2-lipped or almost regular. Stamens 4, arranged in two pairs of unequal length (didynamous). Ovary superior,
1-celled (1-locular), with 2-4 parietal, often deeply lobed placentae; style single; stigma more or less 2-lobed.
Fruit:- A capsule splitting into cells, along the midrib or dorsal suture (loculicidal capsule); seeds small, numerous.
BARTSIA
General description:- Perennial, hemiparasitic herbs with a short, rhizomatous, subterranean stock.
Leaves:- Opposite, sessile, toothed.
Flowers:- In terminal, bracteate, spike-like racemes, which are not directed towards one side (secund). Calyx tubular-bell-shaped (campanulate), 4-toothed. Corolla with a cylindrical tube and 2-lipped limb; upper lip entire or distinctly notched at the apex (emarginate), longer than the lower; lower lip 3-lobed. Stamens 4, didynamous; anthers hairy, ending equally in a sharp point (mucronate) at the base. Stigma pin-headed (capitate).
Fruit:- Capsule loculicidal; seeds c. 2 mm, rather few, with 1 or more longitudinal, membranous wings; hilum lateral.
Key features:-
1) Seeds 1-2 mm, with 1 or more membranous wings, or longitudinally ridged or striate.
2) Rhizomatous perennial herb.
3) Inflorescence not secund.
4) Leaves coarsely serrate.
5) Calyx-tube not keeled.
6) Upper lip of corolla helmet-shaped (galeate) or hooded (cucullata), not beaked (rostrate)
7) Plant glandular-pubescent.
8) Flowers sessile.
CISTANCHE
Stems:- Stout, simple.
Leaves:- Numerous.
Flowers:- Numerous, in dense spikes. Bracteoles 2, adnate to calyx. Calyx campanulate, with 5 equal, obtuse lobes. Corolla scarcely 2-lipped and nearly regular, with campanulate or obconical tube and 5 subequal, patent lobes. Stamens included. Placentae 4, not deeply lobed.
1) Flowers in racemes, spikes or panicles.
2) Corolla ± regular, 5-lobed.
EUPHRASIA
General description:- Annual (rarely perennial) hemiparasitic herbs
Leaves:- Opposite, crenate to incise-dentate.
Flowers:- Zygomorphic, in bracteate, terminal, spike-like racemes. Bracts (floral leaves) large and leaflike; bracteoles absent. Calyx tubular or campanulate, 4-lobed. Corolla white to purple, marked with deep violet lines, and with yellow spots on lower lip and throat; limb 2-lipped, the upper lip galeate, the lower longer, flat, patent, 3-lobed with emarginate lobes. Stamens 4, didynamous; loculi parallel, spurred, one loculus with a much longer spur than the other. Stigma capitate.
Fruit:- Capsule loculicidal; seeds numerous.
Key features:-
1) Calyx-tube usually cylindrical or campanulate, scarcely inflated.
2) Anther-lobes mucronate; one anther-lobe with a longer mucro than the other.
3) Seeds not discoid.
4) Lobes of the upper lip of corolla recurved; lobes of lower lip conspicuously emarginate.
MACROSYRINGION
General description:- Annual, hemiparasitic herbs or dwarf shrubs.
Leaves:- Opposite, sessile, usually narrow, entire or obscurely (rarely conspicuously) toothed.
Flowers:- Zygomorphic, in terminal, bracteate, spike-like, secund racemes. Calyx tubular-campanulate, 4-toothed. Corolla with a cylindrical tube and 2-lipped limb; upper lip entire to shortly 2-lobed, the lobes not recurved; lower lip 3-lobed, with entire or slightly emarginate lobes. Stamens 4, didynamous; anthers glabrous or hairy, equally mucronate at base. Stigma capitate.
Fruits:- Capsule loculicidal; seeds 1-2 mm, rather few, with longitudinal striae or low ridges.
Key features:-
1) Annual herb or dwarf shrub.
2) Seeds with longitudinal striae or low ridges.
3) Inflorescence secund.
4) Leaves usually entire or subentire.
ODONTITES
General description:- Annual, hemiparasitic herbs or dwarf shrubs.
Leaves:- Opposite, stalkless (sessile), usually narrow, entire or obscurely (rarely conspicuously) toothed.
Flowers:- Zygomorphic, in terminal, bracteate, spike-like, directed towards one side (secund) racemes. Calyx tubular-bell-shaped (campanulate), 4-toothed. Corolla with a cylindrical tube and 2-lipped limb; upper lip entire to shortly 2-lobed, the lobes not recurved; lower lip 3-lobed, lobes entire or slightly notched at the apex (emarginate) Stamens 4, didynamous; anthers glabrous or hairy, ending equally in a sharp point (mucronate) at the base. Stigma pin-headed (capitate).
Fruit:- Capsule loculicidal; seeds 1-2 mm, rather few, with longitudinal striae or low ridges.
Key features:-
1) Seeds with longitudinal striae or low ridges
2) Inflorescence secund.
3) Leaves usually entire or subentire.
OROBANCHE
General description:- Perennial, biennial or annual.
Stems:- Stout or slender, simple or branched.
Leaves:- Numerous.
Flowers:- Usually in dense spikes or racemes. Bracteoles, if present, attached to (adnate) to the calyx. Calyx with cylindrical to bell-shaped (campanulate) tube and 4(-5) teeth, or divided, usually deeply, into 2 lateral segments, which may be entire or bifid. Corolla strongly 2-lipped; lower lip 3-lobed, at least as long as the upper. Stamens included. Placentae 4, variably lobed.
Sect. OROBANCHE
Stems:- Simple.
Flowers:- Sessile, without bracteoles. Calyx split above and below almost or completely to the base, and thus divided into 2 lateral segments, which may be entire or equally or unequally bifid. Corolla variously shaped, usually tinged with yellow, brown or red; upper lip 2-lobed to entire.
O. MINOR Group
Stems:- 10-70(-100) x 0·3-1 cm, variably swollen at base, glandular-pubescent to villous, yellowish, more or less tinged with purple, red or brown.
Leaves:- 10-25 mm. Spike 3-30 x 2-4 cm, usually lax below, more or less dense above, glandular-pubescent; bracts 7-22 mm, lanceolate, acuminate.
Flowers:- Calyx 7-16 mm; segments free. Corolla 10-23 mm, erecto-patent (between spreading and erect) to more or less patent, tubular or narrowly bell-shaped (campanulate), curved or nearly straight; lower lip not ciliate. Filaments hairy below (sometimes only sparsely), subglabrous above, inserted 1·5-6 mm above base of corolla; anthers glabrous.
Fruit:- Capsule 8-10 mm.
Sect. TRIONYCHON
Stems:- Simple or branched.
Flowers:- Stemmed (pedicellate) or stemless (sessile), with 2 bracteoles attached to (adnate) to the calyx. Calyx with cylindrical to bell-shaped (campanulate) tube and 4 subequal teeth, rarely with a fifth, much smaller tooth. Corolla white, cream, blue or violet, constricted below the middle near the insertion of the filaments; upper lip 2-lobed.
PARENTUCELLIA
General description:- Annual, hemiparasitic herbs with a short, rhizomatous, subterranean stock.
Leaves:- Opposite, sessile, toothed.
Flowers:- In terminal, bracteate, spike-like racemes, which are not directed towards one side (secund). Calyx tubular-bell-shaped (campanulate), 4-toothed. Corolla with a cylindrical tube and 2-lipped limb; upper lip entire or distinctly notched at the apex (emarginate), shorter than the lower; lower lip 3-lobed. Stamens 4, didynamous; anthers hairy, ending equally in a sharp point (mucronate) at the base. Stigma pin-headed (capitate).
Fruit:- Capsule loculicidal, seeds c. 0·5 mm, numerous, smooth or finely reticulate; hilum basal.
Key features:-
1) Upper lip of corolla entire, or with flat lobes; lobes of lower lip entire or very slightly notched at the apex (emarginate).
2) Anther-lobes equally ending abruptly in a sharp point (mucronate).
3) Seeds c. 0·5 mm, smooth or finely reticulate, not winged.