General description:- Annual to perennial herbs, rarely small shrubs.
Leaves:- Alternate, exstipulate.
Flowers:- Usually hermaphrodite, radially symmetrical (actinomorphic), the sepals, petals and stamens inserted on the receptacle below and free from the ovary (hypogynous). Sepals 4, free, in 2 at right angles to each other (decussate) pairs. Petals 4, rarely absent, free, clawed, overlapping (imbricate) or contorted, alternating with the sepals. Stamens usually 6, rarely 4, 2 or 0, tetradynamous (an outer pair with short filaments, and 2 inner pairs, 1 posterior and 1 anterior, with long filaments); filaments sometimes winged or with a tooth-like appendage. Nectarial glands of various sizes, shapes, colours and dispositions around the base of the stamens and ovary. Ovary of 2 united carpels, (syncarpous), with 2 parietal placentas, usually 2-celled (bilocular) through the formation of a membranous false septum by the union of outgrowths of the placentas, sometimes transversely multi-celled (plurilocular). Stigma capitate to bilobed.
Fruit:- Usually a capsule splitting open to release the seeds (dehiscent) by 2 valves from below, called a siliqua when at least 3 times as long as wide or a silicula if less than 3 times as long as wide; sometimes indehiscent, breaking into 1-seeded portions or not; rarely transversely articulate with dehiscent and indehiscent segments; sometimes dividing at maturity into 1-seeded portions (lomentum).
There is great diversity in the form and structure of the fruit in this family, often affording an easy means of identification, especially in genera which possess a distinctive siliqua or silicula. The seeds are always inserted in 2 rows in each loculus, but where the diameter of the seed is approximately the same as that of the fruit they appear to be in 1 row, and are so described.
Many species in this family, especially among the annuals, are found in Europe principally or exclusively as weeds of cultivation or as ruderals.Double click to edit
AETHIONEMA
General description:- Glabrous, annuals or perennials.
Leaves:- Entire, sessile.
Flowers:- Inflorescence racemose. Sepals erect, the lateral saccate at the base; petals entire; the 4 inner stamens with winged and bent filaments, the wing sometimes ending in a tooth above.
Fruit:- Silicula flattened and winged, bilocular and with narrow partitions (angustiseptate), with 1-4 seeds in each loculus, opening by 2 valves, or unilocular, 1-seeded and indehiscent.
Key features:-
1) Leaves entire, not ± confined to a basal rosette.
2) Sepals erect
A. SAXATILE Group
General description:- Perennials, often woody at the base.
Stems:- 5-35 cm, ascending to erect, usually simple.
Leaves:- Lower, often opposite, obtuse (rarely retuse), the upper acute or obtuse.
Flowers:- Petals white, pink, purplish or lilac.
Fruit:- Silicula 1- to 8-seeded, emarginate at the apex.
Key features:-
1) Upper leaves not cordate-amplexicaul.
2) At least the lower leaves obtuse.
ALYSSUM
General description:- Annuals to perennials, rarely small shrubs; hairs branched or stellate, sometimes mixed with unbranched hairs or the covering (indumentum) of small scales (lepidote).
Stems:- Flowering terminal.
Leaves:- Basal usually similar to the cauline; stalks (petioles) of basal leaves not grooved, not persistent or swollen at the base.
Flowers:- Buds ellipsoidal or oblong-ellipsoidal; sepals erect, not pouch-shaped (saccate) at the base; petals yellow, entire to shallowly divided at the tip in two (bifid); filaments of the long stamens usually winged or toothed, those of the short stamens usually with an appendage.
Fruit:- A flattened 2-locular capsule with the partition across the broad diameter (latiseptate) silicula; valves without a conspicuous median vein; style distinct but often short; stigma capitate or emarginate. Seeds 1 or 2(-8) in each loculus, often winged or margined.
The indumentum is described as dimorphic when it is composed of appressed stellate hairs mixed with long, patent, unbranched or branched hairs, or with stellate hairs with some long, spreading (patent) rays. The measurements given for the diameter of the stellate hairs are for the usually peltate (round and attached at or near the centre) tops of these hairs. Basal leaves are those at the base of non-flowering rosettes or stems.
Key features:-
1) Petals less than 9 mm.
Most species occur in dry, rocky, stony, or sandy places or on cliffs,
Sect. ALYSSUM
General description:- Annuals to perennials.
Flowers:- Inflorescence a simple raceme. Most filaments winged or with appendages. Ovules 2 in each loculus.
Sect. ODONTARRHENA
General description:- Perennials.
Flowers:- Inflorescence a simple or compound raceme. Filaments with wings or appendages. Ovules solitary in each loculus.
ARABIDOPSIS
General description:- Annual to perennial; glabrous or with unbranched and branched hairs.
Leaves:- Entire to pinnatifid.
Flowers:- Sepals not saccate at the base; petals white, pale purple or yellow, sometimes absent.
Fruit:- A siliqua; valves 1-veined; style short; stigma subcapitate. Seeds small (less than 1 mm)
Key features:-
1) Basal leaves attenuate at the base.
2) Seeds less than 1 mm, not winged.
3) Siliqua pubescent; at least 10 mm long and up to 1 mm wide.
4) Petals entire or truncate.
5) Inner sepals not saccate at the base.
AUBRIETA
General description:- Perennial herbs; hairs stellate or both stellate and simple or forked, rarely glabrous.
Leaves:- Simple.
Flowers:- Inner sepals pouch-shaped (saccate); petals pink, purple or violet, long-clawed. Filaments of the outer stamens with a toothed (dentate) appendage. Style distinct; stigma pin-headed (capitate).
Fruit:- A siliqua, rarely a silicula; valves with a median vein. Seeds in 2 rows in each loculus.
1) Silicula sessile.
2) Plant with unbranched, branched or stellate hairs, sometimes mixed with a few medifixed.
3) Style at least 2·5 mm.
4) Petals pink, purple or violet.
All the species are montane or alpine, occurring on rocks and screes and in open coniferous woods.
AURINIA
General description:- Perennials, more or less woody at the base; hairs stellate, branched or with small scales on the surface (lepidote).
Leaves:- Basal leaves considerably larger than the cauline; petioles of basal leaves grooved on the upper surface, with persistent, swollen bases. Flowering stems usually axillary.
Flowers:- Buds globose. Sepals erecto-patent (between spreading and erect), not pouch-shaped (saccate) at the base; petals yellow or white, distinctly notched at the apex (emarginate) or deeply divided at the tip in two (bifid), sometimes entire; filaments not winged or toothed, with very small, suborbicular appendage at the base.
Fruit:- A flattened 2-locular capsule with the partition across the broad diameter (latiseptate), usually globose silicula; valves without a conspicuous median vein; style short; stigma pin-headed (capitate). Seeds (1)2-6(-8) in each loculus, usually winged.
BARBAREA
General description:- Biennials to perennials (rarely annuals); glabrous or with unbranched hairs
Leaves:- Pinnatifid or pinnatisect, the cauline auriculate.
Flowers:-
1) Inner sepals slightly saccate at the base.
2) Petals yellow, indistinctly clawed.
Fruit:-
1) A siliqua, terete to 4-angled.
2) Valves usually with a strong median vein and reticulate lateral veins.
3) Style distinct; stigma entire or slightly 2-lobed.
4) Seeds in 1 row in each loculus.
Key features:-
1) Siliqua not attenuate, keeled; not or only slightly torulose.
2) Seeds in 1 row in each loculus. ovoid, ellipsoidal or oblong, not mucilaginous.
All species occur usually in wet or damp habitats, and some are weeds or ruderals
BISCUTELLA
General description:- Annuals, perennials or small shrubs.
Leaves:- Entire to pinnatifid leaves.
Flowers:- Petals usually clawed, yellow.
Fruit:- A strongly compressed silicula, divided into two lobes (didymous), indehiscent but with the 1-seeded loculi eventually breaking away from the axis; valves glabrous or with simple or clavate hairs; style long. Seeds unwinged.
Key features:-
1) Silicula didymous; flat; not articulated.
2) Petals yellow.
3) Style long.
BRASSICA
General description:- Annuals to perennials or small shrubs.
Leaves:- Entire or divided, the divisions extending from about half to two-thirds of the way towards the midrib (pinnatipartite).
Flowers:- Sepals erect or spreading (patent), the inner larger than the outer; petals yellow or white, clawed. Gynophore (a stalk carrying the ovary) short or absent.
Fruit:- A siliqua with a long or short beak; valves convex, with a prominent median vein. Seeds usually in 1 row in each loculus, at least in the basal ½ of the siliqua, globose or rarely ellipsoidal.
1) Valves of the siliqua 1-veined, sometimes with reticulate lateral veins, or without veins.
2) Siliqua not more than 7 times as long as wide, with a beak at least 5 mm.
3) Lower leaves lobed, sinuate-dentate or sinuate-crenate.
4) Sepals erecto-patent or patent.
5) Cauline leaves toothed or lobed, rarely entire, then not amplexicaul.
6) Leaves all or nearly all basal.
7) Flowering stem leafy.
8) Valves of the siliqua rounded on the back.
9) Seeds globose; in 1 row in each loculus.
BUNIAS
General description:- Annuals to perennials; glabrous or with glandular, unbranched or branched hairs.
Leaves:- Entire to pinnatisect.
Flowers:- Sepals erecto-patent, the inner not or scarcely saccate at the base; petals white or yellow.
Fruit:- An indehiscent silicula with irregular longitudinal wings, ridges or protuberances, and with 1-4 1-seeded loculi; style distinct; stigma capitate.
1) Silicula without 2 sterile loculi side by side.
2) Silicula with 4 longitudinal wings or ridges or covered with irregular protuberances.
CAKILE
General description:- Glabrous, annuals, covered with a waxy bloom (glaucous).
Leaves:- Succulent.
Flowers:- Petals clawed, violet, pink or white.
Fruit:- A transversely articulate siliqua; upper segment larger, ovoid, more or less 4-angled, not attenuate into style, with 1(2) seeds; lower obconical, not evidently 2-valved, usually with a single seed, indehiscent.
1) Valves of the siliqua 1-veined, sometimes with reticulate lateral veins, or without veins.
2) Siliqua with a distinct transverse articulation, the lower segment sometimes sterile and stipitiform.
3) Plant with obvious aerial stem.
4) Pedicels not curving downwards to bury the fruit.
5) Upper segment of fruit oblong-ovoid, mostly at least twice as long as wide.
CALEPINA
General description:- Annuals to perennials; glabrous or with unbranched hairs.
Flowers:- Sepals erecto-patent; petals white, with a short claw or cuneate at the base; filaments without appendages.
Fruit:- A transversely articulate silicula; ovoid-globose ending in a short, thick beak; lower segment absent, sterile, forming a stalk together with the gynophore; upper segment ovoid to globose, not splitting open to release their seeds (indehiscent), and falling early (caducous), with a single pendent seed; stigma sessile.
Key features:-
1) Upper segment of the fruit beaked, or with a distinct persistent style.
2) Cauline leaves amplexicaul, with acute auricles.
3) Plant green, glabrous or sparsely hairy.
4) Silicula with a short, broad, obtuse beak.
5) Petals unequal, the inner distinctly longer than the outer.
CAPSELLA
General description:- Annuals or biennials; glabrous or with branched and unbranched hairs.
Leaves:- Basal entire to pinnatifid; cauline leaves sagittate-amplexicaul.
Flowers:- Inflorescence racemose, ebracteate. Sepals erect, not saccate; petals white, pink or yellowish; stamens without appendages.
Fruit:- An angusti-septate (with narrow partitions) silicula, usually triangular-obcordate; valves keeled, reticulately veined; style distinct; stigma minute, pin-headed (capitate). Seeds up to 12 in each loculus.
Key features:-
1) Valves of fruit not winged or keeled, or with a weak keel.
2) Fruits triangular-obcordate.
The species are usually plants of cultivated or waste ground.
CARDAMINE
General description:- Annuals to perennials; glabrous or with simple hairs.
Leaves:- Simple to pinnate.
Flowers:- Inner sepals pouch-shaped (saccate) or not. Petals white, pink or purple (rarely pale yellow). Style short or distinct; stigma slightly 2-lobed.
Fruit:- A strongly compressed siliqua; valves coiling spirally from the base at dehiscence, veinless or with an indistinct median vein; Seeds in 1 row in each loculus.
1) Siliqua more than 7 times as long as wide, strongly compressed.
2) Valves flat, coiling spirally from the base on dehiscence.
CARRICHTERA
General description:- Annual with unbranched hairs
Leaves:- Simple.
Flowers:- Inflorescence leaf-opposed. Sepals erect; filaments free.
Fruit:- A transversely articulate, deflexed silicula, lower segment ellipsoidal, with 2 naviculiform, 3-veined valves, upper segment sterile, strongly compressed, foliaceous, cochleariform.
Key features:-
1) Fruit pendent or patent, not more than 8 mm.
CLYPEOLA
General description:- Annuals; hairs branched or stellate.
Flowers:- Sepals erecto-patent, not pouch-shaped (saccate); petals yellow, shortly clawed.
Fruit:- An indehiscent, compressed, 1-seeded, pendent silicula; style short; stigma obtuse.
Key features:-
1) Fruit not convex beneath and not concave with incurved margins above.
2) Hairs branched or stellate.
3) Petals yellow.
CORONOPUS
General description:- Annuals to perennials, or with unbranched hairs.
Flowers:- Raceme leaf-opposed. Sepals patent; petals white, small or absent; stamens 2-6.
Fruit:- An angusti-septate silicula, indehiscent or breaking in 2 halves; valves subglobose, verrucose or reticulate. Seeds 2.
CRAMBE
General description:- Annuals to perennials; glabrous or with unbranched hairs.
Flowers:- Sepals between spreading and erect (erecto-patent); petals white, with a short claw or wedge-shaped (cuneate) at the base; filaments of inner stamens usually with a tooth-like appendage.
Fruit:- A transversely articulate silicula; lower segment short, sterile, forming a stalk together with the gynophore; upper segment ovoid to globose, indehiscent, falling off early (caducous), with a single pendent seed; stigma sessile.
DESCURAINIA
General description:- Annual or biennial; hairs of 2 kinds, dendritic and unbranched.
Leaves:- 2- to 4-pinnatisect.
Flowers:- Sepals not saccate; petals pale yellow, smaller than the sepals. Style very short; stigma subcapitate.
Fruit:- A siliqua; valves with a distinct median vein. Seeds small (not more than 1 mm), not mucilaginous when moistened.
Key features:-
1) Siliqua without horns at the apex.
2) Leaves 2- to 4-pinnatisect.
3) Petals shorter than the sepals.
4) Siliqua 0·5-1 mm wide.
5) Seeds 0·8-1 mm.
DIDESMUS
General description:- Annuals to perennials, with unbranched hairs.
Flowers:- Sepals erectopatent; petals white, with a short claw.
Fruit:- A transversely articulate silicula; lower segment cylindrical, with (0)1-3 seeds upper segment of silicula as wide as the lower segment, tetragonal; indehiscent, falling (caducous) at maturity, with a single erect seed; beak long, pungent..
Key features:-
1) Cauline leaves not amplexicaul.
2) Petals white.
3) Upper segment of fruit with a pungent beak.
DIPLOTAXIS
General description:- Annuals to perennials.
Leaves:- Entire to pinnatipartite.
Flowers:- Sepals erecto-patent; petals clawed, usually yellow. Gynophore usually short.
Fruit:- An elongate, linear siliqua with a short beak; valves compressed, with a prominent median vein. Seeds usually in 2 rows in each loculus, ovoid or ellipsoidal.
Key features:-
1) Valves with distinct median vein.
2) Seeds in 2 or more rows in each loculus.
3) Siliqua with a distinct beak or style up to 7 mm.
4) Cauline leaves cuneate or hastate at the base.
DRABA
General description:- Annuals to perennials.
Leaves:- Simple, entire or dentate.
Flowers:- Sepals erecto-patent (between spreading and erect), the inner not or only slightly pouch-shaped (saccate) at the base; petals white or yellow, entire or distinctly notched at the apex (emarginate); filaments not or only slightly dilated at the base.
Fruit:- A flattened 2-locular capsule with the partition across the broad diameter (latiseptate) silicula or siliqua; valves more or less flat, with a median vein in the lower ½; stigma pin-headed (capitate). Seeds in 2 rows in each loculus, not winged. Radicle accumbent.
Most of the species are arctic or montane, growing in open, rocky or gravelly places. Several are widely grown for ornament as rock-plants in gardens.
The nature and density of the indumentum is used a great deal in the taxonomy of Draba. The hairs may be unbranched, branched, stellate or medifixed. The leaves are nearly always ciliate even when they are otherwise glabrous. The length of the stem refers to the fruiting stage; there is often considerable elongation after flowering.
Key features:-
1) Leaves simple, usually entire, linear to narrowly spathulate, rarely obovate.
2) Cauline leaves cuneate to truncate at the base, not amplexicaul.
3) Leafless stem bearing flowers (scape), rarely with few cauline leaves.
4) Siliqua 3-7 times as long as wide.
5) Radicle accumbent; usually with at least some stellate or branched hairs.
6) Petals entire or emarginate, not more than 8 mm.
7) Valves of the silicula ± flat.
8) Seeds in two rows and numerous in each loculus, ovules also numerous.
9) Filaments of the inner stamens not winged.
Sect. AIZOPSIS
General description:- Scapose, caespitose perennials, often densely pulvinate (a swelling on the petiole that functions to allow the leaf movement).
Leaves:- Rigid, entire, linear or narrowly spathulate, arranged in a rosette (rosulate), margins fringed with hairs (ciliate).
Flowers:- Yellow.
Sect. DRABELLA
General description:- Annuals, biennials or perennials, with leafy stems and small, pale yellow to white flowers. Style very short.
ENARTHROCARPUS
General description:- Annuals, with unbranched hairs.
Flowers:- Raceme bracteate. Sepals erecto-patent (between spreading and erect); petals clawed, yellow, with violet veins.
Fruit:- A transversely articulate, non-septate siliqua; the lower segment 2-valved, indehiscent, seedless or with 1 or 2 seeds; the upper segment linear, elongate, caducous, with 3-15 seeds, constricted between the seeds and separating into 1-seeded portions.
Key features:-
1) Cauline leaves not cordate-amplexicaul, usually toothed or lobed
2) Siliqua with a short stipitate segment at the base, separated from the rest of the siliqua by an articulation
3) Racemes bracteate, at least in the lower ½.
ERUCA
General description:- Annuals or perennials.
Leaves:- Pinnatifid or pinnatisect.
Flowers:- Sepals erect, unequal, the inner somewhat saccate at the base; petals yellow, clawed.
Fruit:- A siliqua with a long beak; valves distinctly 1-veined. Seeds in 2 rows in each loculus, globose.
Key features:-
1) Fruit with 2 segments, the upper flat, leaf-like (foliaceous) or tongue-shaped (lingulate), the lower with 1 or 2 seeds.
2) Filaments free.
3) Fruit erect or erecto-patent (between spreading and erect), 12-35 mm.
4) Siliqua with a beak 5-12 mm, shorter than the rest of the siliqua; seeds in 2 rows in each loculus.
ERUCARIA
General description:- Annual or biennial; hairs unbranched.
Flowers:- Sepals erect; petals with a long claw, lilac.
Fruit:- A transversely articulate siliqua with both segments fertile, the lower 2-valved and dehiscent, the upper abruptly contracted into the style.
Key features:-
1) Petals purple.
2) Siliqua not more than 2 cm, erect and closely appressed to the stem.
ERYSIMUM
General description:- Annuals to perennials, with branched hairs.
Flowers:- Sepals erect, the inner usually pouch-shaped (saccate) at the base; petals yellow, rarely purple or brownish, long-clawed; median nectaries usually present.
Fruit:- A siliqua valves usually 1-veined, the hairs not lying transversely across the valves; style distinct, not more than 1/3 as long as the rest of the siliqua, rarely absent; stigma usually weakly 2-lobed. Seeds in 1(2) rows in each loculus.
Distinguishing features:-
1) Inner sepals strongly saccate at the base.
2) Filaments all free.
3) Siliqua not articulated; usually more than 0·8 mm wide.
4) Plant ± densely covered with hairs attached at or near the middle (medifixed).
5) Style at least 2 mm in fruit.
6) Flowering stem leafy.
7) Petals white, pink or purple.
FIBIGIA
General description:- Perennials; hairs mostly stellate, rarely a few simple.
Flowers:- Sepals erect; petals yellow, shortly clawed.
Fruit:- Fruit a strongly compressed latiseptate silicula; valves flat, not veined; style long; stigma more or less capitate. Seeds 2-8 in each loculus, winged.
Key features:-
1) Petals short-clawed; yellow or white
2) Silicula compressed
HORNUNGIA
General description:- Small annuals; hairs stellate or absent.
Flowers:- Inflorescence ebracteate. Petals white, short-clawed.
Fruit:- A silicula laterally compressed with a narrow septum (angustiseptate) (dividing wall or enclosure), elliptical to oblong-ovate. Seeds 1 or 2 in each loculus, slimy (mucilaginous).
HYMENOLOBUS
General description:- Small perennials with unbranched hairs.
Flowers:-
1) Inflorescence ebracteate.
2) Petals white, clawed.
Fruit:-
1) Silicula, elliptical to lanceolate. flattened at right angles to the septum so the septum crosses the narrowest part of the ovary (angusti-septate).
2) Seeds 3-10 in each loculus; hairs unbranched when present.
3) Valves of fruit ± strongly compressed.