1. Brassicaceae Burnett

    1. This family is accepted.

[NTK]

Al-Shehbaz, I.A. (2012). Neotropical Brassicaceae.

Morphology
Description

Herbs, annual , biennial , or perennial , sometimes subshrubs or shrubs, very rarely lianas; taprooted or with few to many-branched and slender or woody caudex, sometimes with slender or tuberous rhizomes, rarely stoloniferous; terrestrial or rarely submerged aquatics, with a pungent watery juice, without or rarely with multicellular glandular papillae or tubercles.  Trichomes unicellular, simple , stalked or sessile , 2-many forked, stellate , dendritic or malpighiaceous (medifixed, bifid, appressed ), rarely peltate and scalelike, eglandular.  Stems erect , ascending or prostrate , herbaceous or rarely woody , leafy or leafless, sometimes absent.  Leaves exstipulate or rarely with tiny, stipule -like glands at base of petioles and pedicels, simple , entire or variously dissected , rarely trifoliolate or pinnately compound ; basal leaf rosette present or absent; cauline leaves almost always alternate or rarely opposite, petiolate or sessile , sometimes absent.  Inflorescences racemes, corymbs, or panicles, ebracteate or less frequently bracteate, sometimes flowers solitary on pedicels originating from axils of rosette leaves; pedicels persistent with fruit , variously oriented.  Flowers hypogynous, actinomorphic , bisexual ; sepals 4, in 2 decussate pairs (1 pair lateral and 1 median), free or rarely united, not saccate or lateral (inner) pair saccate, caducous or rarely persistent , erect , ascending , spreading or reflexed , forming tubular, campanulate or urceolate calyx ; petals 4, alternate with sepals, arranged in the form of a cross (cruciform; hence the earlier family name Cruciferae), rarely rudimentary or absent, differentiated or not into blade and claw , basally unappendaged; blade entire or emarginate , sometimes reduced and much smaller than well-developed claws; stamens 6, in 2 whorls,  tetradynamous ( lateral (outer) pair shorter than median (inner) 2 pairs), rarely equal in length, sometimes stamens 2 or 4; filaments slender, median pairs free ; anthers dithecal, dehiscing by longitudinal slits; pollen grains 3-colpate, trinucleate; nectar glands receptacular, highly diversified in number, shape, size, and disposition around filament bases, always present opposite bases of lateral filaments, median glands present or absent; pistil 1, 2-carpelled; ovary superior , sessile or borne on a distinct gynophore , 2-locular and with a false septum connecting 2 placentae, rarely unilocular and eseptate; placentation parietal , rarely apical; ovules 1-300 per ovary , anatropous or campylotropous, bitegmic, crassinucellate or rarely tenuinucellate.  Fruits typically 2-valved capsules, arbitrarily termed silique ( siliqua ) when length at least 3  width, or silicle (silicula) when length less than 3  width, dehiscent or indehiscent , sometimes nutletlike, lomentaceous, samaroid, or schizocarpic, segmented or not, terete , angled, latiseptate (flattened parallel to septum), or angustiseptate (flattened at a right angle to septum); gynophore absent or sometimes distinct; valves dehiscing acropetally or rarely basipetally; replum ( persistent placenta ) rounded or flattened; septum complete, perforated, or reduced to a rim; style 1, persistent , sometimes obsolete or absent; stigma capitate or conical, entire or 2- lobed , lobes spreading or connivent , sometimes decurrent , free or connate Seeds usually yellow or brown, flattened or plump, ovoid , oblong , globose , orbicular or ovate , uniseriately or biseriately arranged in each locule , rarely aseriate, winged or wingless, mucilaginous or not when wetted; embryo strongly curved; cotyledons entire or emarginate , variously oriented in relation to radicle: incumbent (embryo notorrhizal: radicle lying along back of 1 cotyledon ), accumbent (embryo pleurorrhizal: radicle applied to margins of both cotyledons), conduplicate (embryo orthoplocal: cotyledons folded longitudinally around radicle); endosperm absent; germination epigeal.

General Description
Notes on delimitation
  • The Brassicaceae (also known as Cruciferae) is type family of the order Brassicales that includes 17 other families, including the sister family Cleomaceae.
  • The tribal classification of the family has been quite controversial, but extensive molecular studies during the past decade have been synthesized to produce a new phylogenetic tribal classification summarized by Al-Shehbaz (2012) into a family-wide generic and tribal synopsis. In this new classification system, the small SW Asian-Mediterranean tribe Aethionemeae (ca. 45 spp.) is sister to the rest of the family which is divided into three major lineages.
  • The small tribes Eudemeae (7 genera, 31 spp.), Cremolobeae (2 genera, 32 spp.), and Schizopetaleae (2 genera, 16 spp.) are endemic to South America, and their centres of diversity are in the Neotropics.
  • The New World tribes Thelypodieae and Halimolobeae, but not Physarieae, are more diversified in the Neotropics than in North America. Draba L.(ca. 390 spp. worldwide) is represented in South America by 70 species, all except four of which are endemic to the Neotropics.
Number of genera

There are 274 genera in the Neotropics, of which 36 are naturalised

  • Aschersoniodoxa Gilg & Muschl. (4 spp.) 
  • Barbarea W.T. Aiton (1 sp. naturalised)
  • Brassica L. (5 spp. naturalised)
  • Brayopsis Gilg & Muschl. (6 spp.)
  • Cakile Mill. (1 sp.)
  • Capsella Medik. (1 sp. naturalised)
  • Cardamine L. (14 spp. and 3 spp. naturalised) 
  • Cremolobus DC. (7 spp.) 
  • Dactylocardamum Al-Shehbaz (1 spp.)
  • Descurainia Webb & Berthel. (7 spp.)
  • Dictyophragmus O.E. Schulz (2 spp.)
  • Diplotaxis DC. (1 sp. naturalised)
  • Draba L. (66 spp.) 
  • Englerocharis Muschl. (4 spp.)
  • Eruca Mill. (1 sp. naturalised)
  • Erysimum L.(1 sp.)
  • Eudema Humb. & Bonpl. (4 spp.)
  • Exhalimolobus Al-Shehbaz & C.D. Bailey (4 spp.)
  • Hirschfeldia Moech (1 sp. naturalised)
  • Hornungia Rchb. (1 sp. naturalised) 
  • Iberis L. (2 spp. naturalised)
  • Isatis L. (1 sp. naturalised)
  • Lepidium L. (29 spp. & 1 naturalised)
  • Lobularia Desv. (1 sp. naturalised)
  • Mancoa Wedd. (3 spp.)
  • Mathewsia Hook. & Arn. (4 spp.)
  • Matthiola W.T. Aiton (2 spp. naturalised)
  • Menonvillea DC. (6 spp.)
  • Mostacillastrum O.E. Schulz (13 spp.)
  • Nasturtium W.T. Aiton (1 sp. & 1 sp naturalised)
  • Neuontobotrys O.E. Schulz (9 spp.)
  • Pennellia Nieuwl. (4 spp.)
  • Petroravenia Al-Shehbaz (1 sp.)
  • Physaria (Nutt. ex Torr. & A. Gray) A. Gray (1 sp.)
  • Polypsecadium O.E. Schulz (8 spp.)
  • Raphanus L. (2 spp. naturalised)
  • Rapistrum Crantz (1 sp. naturalised)
  • Romanschulzia O.E. Schulz (4 spp.)
  • Rorippa Scop. (12 spp. and 3 spp. naturalised)
  • Sibara Greene (5 spp.)
  • Sinapis L. (2 spp. naturalised)
  • Sisymbrium L. (4 spp. naturalised)
  • Thlaspi L. (1 sp. naturalised)
  • Weberbauera Gilg & Muschl. (16 spp.)

 

General notes
  • The Brassicaceae include several important crop plants grown in the Neotropics as vegetables (e.g., species of Brassica and Raphanus).
  • The only native Neotropical crop is Lepidiummeyenii (maca) cultivated in the high Peruvian Andes and consumed locally.
  • Vegetable oils of various Brassica species, especially B. napus L. (canola), probably rank first in terms of the world's tonnage production, but have not been grown in our area.
  • Several ornamentals are listed above, and 27 of the 36 naturalized species are weedy elsewhere. Lepidium didymum L. and L. bonariense L. are among that notable native South American weeds that have become naturalized elsewhere in the world.
  • The native species of our area grow (Neotropics?) primarily at high altitudes, and only some species of Rorippa and Cardamine grow in typical tropical lowlands.
Status
  • Genera Aschersoniodoxa, Brayopsis, Cremolobus, Dactylocardamum, Englerocharis, and Eudema are endemic. The vast majority of native species (ca. 210 spp.) are endemic to the Neotropics.
  • Three species of Brassica (cabbage, cauliflower, turnip) and one of Raphanus (radish) are cultivated crops and also naturalized.
  • Lobularia maritima (L.) Desv. is a cultivated ornamental widely naturalized. Less commonly naturalized are Malcolmia maritima (L.) W.T. Aiton, Matthiola incana (L.) W.T. Aiton, and Iberis species.
Distribution
Distribution in the Neotropics
  • The Neotropical Brassicaceae include 274 species in 45 genera, of which the 238 native species belong to 28 genera.
  • The 36 naturalized species belong to 21 genera of which four have both native and introduced species.
  • The most speciose genera are Draba and Lepidium (see below).
Diagnostic
Distinguishing characters (always present)
  • The Brassicaceae are easily distinguished by the cruciform corolla and tetradynamous stamens (see family description). The exceptions are in some species of Lepidium that have only two stamens and a rudimentary or absent corolla.
  • The characteristic capsule (often called silique or silicle; see above) is distinctive in the family for all species with dehiscent fruits, in which the fruit valves fall off and the 'false' septum remains.
Other important characters
  • The three distinctive features above collectively occur in the vast majority of species, and when one or two features do not apply then the third would help. For example, in Lepidium spp. with two stamens and apetalous flowers, the fruit type described above is distinctive.
  • In genera such as Isatis and Rapistrum, both with indehiscent fruits and naturalized species in the Neotropics, species are easily placed in the family by the cruciform corolla and tetradynamous stamens.
Key differences from similar families
  • From the sister family Cleomaceae, the Neotropical Brassicaceae are easily distinguished by having actinomorphiccorolla, fruit septum, and curved embryos without a gap between the radicle and cotyledons, as well as by lacking the stipules and palmately compound leaves.
Notable genera and distinguishing features

Only native ones: see terminology in family description

  • Aschersoniodoxa: scapose plants with large, oblanceolate, flattened fruits.
  • Brayopsis: flowers and fruits on solitary pedicels originating from a perennialrosette.
  • Cakile: seashore plants with corky, 2-segmented fruits.
  • Cardamine: often compound leaves and linear fruits with flattened replum.
  • Descurainia: 2- or 3-pinnatisect leaves, dendritic trichomes, dehiscent siliques.
  • Lepidium: flattened, angustiseptate, 2-seeded dehiscent silicles.
  • Mancoa: angustiseptate, many-seeded fruits and branched trichomes.
  • Mathewsia: subshrubs with yellow flowers, dendritic trichomes, and broadly flattened large fruits.
  • Romanschulzia: filaments spreading, equal in length, strongly enlarged at base; sepals spreading, soon falling.
Useful tips for generic identification

Interactive key to the genera of the world:

http://flora.huh.harvard.edu/Brassicaceae/navikey/Brassicaceae_Genera_World/Brassicaceae_Genera_World_NaviKey.html

Literature
Important literature

Al-Shehbaz, I.A. 2012. A generic and tribal synopsis of the Brassicaceae (Cruciferae). Taxon (in press).

Al-Shehbaz, I.A., M. A. Beilstein & E. A. Kellogg. 2006. Systematics and phylogeny of the Brassicaceae: an overview. Pl. Syst. Evol. 259: 89 120.

Al-Shehbaz, I.A. and co-workers. 2010. Brassicaceae. In: Flora of North America Editorial Committee (eds.), Flora of North America vol. 7, pp. 224-746. Oxford University Press, New York.

Appel, O. & I.A. Al-Shehbaz. 2003. Cruciferae. In: Kubitzki, K. & Bayer, C. (eds.), Families and Genera of Vascular Plants, vol. 5, pp. 75 174. Springer Verlag, Heidelberg, Berlin.

Schulz, O.E. 1936. Cruciferae. In: Engler, A. & Harms, H. (eds.), Die natürlichen Pflanzenfamilien, vol. 17B, pp. 227 658. Verlag von Wilhelm Englemann, Leipzig.

Warwick, S.I., Mummenhoff, K., Sauder, C.A., Koch, M.A. & Al-Shehbaz, I.A. 2010. Closing the gaps: phylogenetic relationships in the Brassicaceae based on DNA sequence data of nuclear ribosomal ITS region. Pl. Syst. Evol. 285: 209-232.

[FZ]

Cruciferae, A. W. Exell. Flora Zambesiaca 1:1. 1960

Habit
Annual, biennial or perennial herbs (rarely somewhat shrubby) with alternate (rarely opposite or verticillate) exstipulate, simple or compound leaves sometimes forming a basal rosette
Inflorescences
Inflorescence usually racemose
Flowers
Flowers actinomorphic (except for the stamens) usually bisexual, hypogynous
Calyx
Sepals 4, free, in two series, often somewhat saccate
Corolla
Petals 4 (rarely fewer or absent)
Androecium
Stamens usually 6, tetradynamous (rarely fewer or numerous); anthers 2- (rarely 1-) thecous, opening lengthwise
Gynoecium
Ovary sessile (rarely stipitate), syncarpous of 2 carpels, 1-locular with 1–2 parietal placentas or divided into 2 chambers by a false septum
Fruits
Fruit usually a dehiscent silique or silicule (more rarely indehiscent or transversely or longitudinally jointed)
Seeds
Seeds 1 to numerous, with no or very little endosperm
[FTEA]

Cruciferae, Bengt Jonsell (University of Stockholm). Flora of Tropical East Africa. 1982

Habit
Herbs, sometimes subshrubs (very rarely small trees)
Leaves
Leaves alternate, basal ones often in a rosette, not stipulate, ± petiolate, entire to variously divided
Inflorescences
Inflorescences terminal or sometimes axillary racemes, in flower mostly condensed and often corymbose, in fruit elongate, usually ebracteate
Flowers
Flowers hermaphrodite, actinomorphic or slightly zygomorphic, hypogynous, 4-merous, heterochlamydous
Calyx
Sepals 4, free, imbricate, the inner ones quite often saccate
Corolla
Petals 4 (rarely absent), free, usually equal, ± clawed, imbricate or contorted
Androecium
Stamens 6, tetradynamous (rarely 4 or 2), usually free; anthers usually 2-thecous, opening lengthwise; pollen grains mostly 3-, 4- or multicolpate
Nectaries
Nectarial glands variously arranged at the filament-bases
Gynoecium
Ovary superior, sessile or stipitate, of seemingly 2 united carpels, divided into 2 “secondary” locules by a thin membranous septum (sometimes transversely locular); placentation parietal; ovules usually many, ana- or campylotropous; stigma bifid or connate
Fruits
Fruit a bivalved dehiscent siliqua or silicula (see key), sometimes a nutlet, lomentum or otherwise constructed
Seeds
Seeds virtually devoid of endosperm, with cotyledons incumbent, accumbent or variously folded

Images

Brassicaceae Burnett appears in other Kew resources:

First published in Outlines Bot. (Burnett) 854, 1093, 1123. 1835 [Feb 1835] ; nom. alt.: Cruciferae. (1835)

Accepted by

  • APG IV (2016) http://dx.doi.org/10.1111/boj.12385

Sources

Flora Zambesiaca
Flora Zambesiaca
http://creativecommons.org/licenses/by-nc-sa/3.0

Flora of Tropical East Africa
Flora of Tropical East Africa
http://creativecommons.org/licenses/by-nc-sa/3.0

Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2018. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Neotropikey
Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics.
http://creativecommons.org/licenses/by/3.0

Plants and People Africa
Common Names from Plants and People Africa http://www.plantsandpeopleafrica.com/
© Plants and People Africa http://www.plantsandpeopleafrica.com http://creativecommons.org/licenses/by/3.0/