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Arabis fructicosa

(Fruit Rock Cress)

Overview

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Extirpated
Threat status

Common Names

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Common Names in English:

Fruit Rock Cress, Fruit Rockcress

Description

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Family Brassicaceae

Herbs annual , biennial, or perennial , sometimes subshrubs or shrubs , with a pungent , watery juice. Eglandular trichomes unicellular, simple , stalked or sessile, 2- to many forked , stellate , dendritic , or malpighiaceous (medifixed , bifid, appressed ), rarely peltate and scalelike; glandular trichomes multicellular, with uniseriate or multiseriate stalk . Stems erect , ascending , or prostrate , sometimes absent. Leaves exstipulate , simple, entire or variously pinnately dissected , rarely trifoliolate or pinnately, palmately, or bipinnately compound ; basal leaf rosette present or absent; cauline leaves almost always alternate, rarely opposite or whorled , petiolate or sessile, sometimes absent. Inflorescence bracteate or ebracteate racemes , corymbs, or panicles, sometimes flowers solitary on long pedicels originating from axils of rosette leaves . Flowers hypogynous, mostly actinomorphic . Sepals 4, in 2 decussate pairs, free or rarely united , not saccate or lateral (inner) pair saccate. Petals 4, alternate with sepals, arranged in the form of a cross (cruciform ; hence the earlier family name Cruciferae), rarely rudimentary or absent. Stamens 6, in 2 whorls, tetradynamous (lateral (outer) pair shorter than median (inner) 2 pairs), rarely equal or in 3 pairs of unequal length , sometimes stamens 2 or 4, very rarely 8-24; filaments slender, winged , or appendaged, median pairs free or rarely united; anthers dithecal , dehiscing by longitudinal slits. Pollen grains 3-colpate, trinucleate . Nectar glands receptacular , highly diversified in number, shape , size, and disposition around base of filaments, always present opposite bases of lateral filaments, median glands present or absent. Pistil 2-carpelled; ovary superior, sessile or borne on a distinct gynophore , mostly 2-locular and with a false septum connecting 2 placentae; placentation parietal , rarely apical; ovules anatropous or campylotropous, bitegmic, 1 to many per locule. Fruit typically a 2-valved capsule, generally termed silique (siliqua) when length 3 × or more than width , or silicle (silicula) when length less than 3 × width, dehiscent or indehiscent, sometimes schizocarpic, nutletlike, lomentaceous , or samaroid , segmented or not, terete , angled , or flattened parallel to septum (latiseptate ) or at a right angle to septum (angustiseptate) ; valves 2(or 3-6) ; replum (persistent placenta) rounded , rarely flattened or winged; septum complete, perforated, reduced to a rim , or lacking; style 1, distinct, obsolete , or absent; stigma capitate or conical , entire or 2-lobed, sometimes lobes decurrent and free or connate . Seeds without endosperm, uniseriately or biseriately arranged in each locule, aseriate when 1, winged or wingless, mucilaginous or not when wetted; cotyledons incumbent (embryo notorrhizal: radicle lying along back of 1 cotyledon), accumbent (embryo pleurorrhizal: radicle applied to margins of both cotyledons), or conduplicate (embryo orthoplocal: cotyledons folded longitudinally around radicle), rarely spirally coiled (embryo spirolobal) . Germination epigeal.

About 330 genera and 3500 species: all continents except Antarctica, mainly in temperate areas, with highest diversity in Irano-Turanian, Mediterranean, and W North American regions; 102 genera (eight endemic) and 412 species (115 endemic) in China.

Because of lack of a comprehensive classification based on phylogenetic relationships among genera, and in order to facilitate direct comparison between the accounts in FOC and FRPS, the sequence of genera follows Schulz (Nat. Pflanzenfam. 17b: 227-658. 1936) . However, it should be emphasized that his system is largely artificial because he placed closely related genera in different tribes and remotely related genera in the same tribe. For example, Arabis, Aubrieta, Draba, and Macropodium, which are very closely related on the basis of recent molecular studies, were placed by Schulz in four different tribes, whereas the unrelated Capsella, Lepidium, and Thlaspi were placed in one tribe. The delimitation of genera is often difficult, and mature fruits are needed for reliable identification.

The Brassicaceae include many important crop plants that are grown as vegetables (Brassica, Nasturtium, Raphanus) and sources of vegetable oils (Brassica) and condiments (Armoracia, Brassica, Eutrema, Sinapis) . Oils of Brassica probably rank first in terms of tonnage of the world's production of edible oils. The family includes many ornamentals in the genera Erysimum, Iberis Linnaeus, Lobularia, Malcolmia, and Matthiola. Of these, only Lobularia maritima has become naturalized in China. The family also includes more than 120 species of weeds . Arabidopsis thaliana, which is naturalized in China, has become the model organism in many fields of experimental biology .

The delimitation of genera in the Brassicaceae is often difficult because of the frequent independent evolution of what appear to be similar character states , the variability of a given character in one genus and its fixture in another, and the inadequate sampling of material by most authors . Fruit characters are essential in the identification of genera. However, a key emphasizing flowering material is given in addition to the one emphasizing fruit. The most reliable determination of genera can be achieved when the material has both fruit and flowers and when both keys are successfully used to reach the same genus.

The types of cotyledonary position, which in reality is the position of the radicle in relation to the cotyledons (e.g. , radicle accumbent, incumbent, or conduplicate, though radicle referred to as "cotyledon" throughout) are important in the separation of many genera, and a cross section of the seed provides the easiest and simplest way of determining that position. The exact number of ovules per ovary can easily be determined from the fruit because aborted ovules persist through fruit dehiscence. However, it is more laborious to determine the ovule number from pistils and young fruit.[1]

Subfamily Faboideae

Mostly herbs, shrubs , or trees . Leaves pinnate or palmate to trifoliolate or apparently simple . Corolla usually, showy, zygomorphic, the petals imbricate, posterior (upper or banner ) petal outermost in bud. Stamens 10 or 9 + 1 (diadelphous ), not showy. Pollen released in monads . Seeds with u-shaped line (pleurogram) lacking. [Carr]

Genus Arabis

Herbs annual , biennial, or perennial , rarely subshrubs or shrubs . Trichomes stellate , dendritic , or stalked forked , sometimes mixed with fewer simple ones, rarely primarily simple. Stems simple or branched apically. Basal leaves petiolate , rosulate, simple, often entire, sometimes dentate , rarely lyrate-pinnatifid. Cauline leaves sessile and auriculate , sagittate , or amplexicaul , very rarely petiolate, entire or dentate. Racemes ebracteate or rarely bracteate throughout or only basally, sometimes in panicles, elongated in fruit. Fruiting pedicels erect , ascending , divaricate , or reflexed . Sepals ovate or oblong , base of lateral pair saccate or not, margin membranous. Petals white, pink, or purple; blade spatulate , oblong, or oblanceolate , rarely obovate , apex obtuse or emarginate ; claw shorter than sepals. Stamens 6, tetradynamous ; filaments usually not dilated at base; anthers ovate, oblong, or linear , obtuse at apex. Nectar glands confluent , subtending bases of all stamens; median glands sometimes toothlike and free , rarely absent; lateral glands semiannular or annular . Ovules 12-110 per ovary. Fruit dehiscent siliques, linear, latiseptate , sessile or rarely shortly stipitate ; valves papery , with an obscure or prominent midvein , smooth or torulose ; replum rounded ; septum complete , membranous, translucent , veinless; style obsolete or distinct ; stigma capitate, entire or slightly 2-lobed. Seeds uniseriate or biseriate , winged or margined , oblong or orbicular , flattened; seed coat smooth or minutely reticulate , not mucilaginous when wetted; cotyledons accumbent .

About 70 species: temperate Asia, Europe, North America; 14 species (one endemic) in China.

The limits of Arabis are highly artificial, and the genus is defined primarily on the basis of having branched trichomes, flattened, linear fruit, and accumbent cotyledons . However, this combination of characters has evolved independently several times in the Brassicaceae. A critical study of the genus on worldwide basis is much needed.[2]

Physical Description

Habit: Forb/herb

Biology

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Reproduction

Duration: Perennial

Taxonomy

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Notes

Name Status: Accepted Name . Latest taxonomic scrutiny: 15-Mar-2000

Similar Species

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Members of the genus Arabis

ZipcodeZoo has pages for 791 species, subspecies, varieties, forms, and cultivars in this genus. Here are just 100 of them:

A. abietina · A. accedens · A. aculeolata (Waldo Rock-Cress) · A. acutina · A. aizoides · A. alanyensis · A. alaschanica · A. albertina · A. albida · A. alliaria · A. allionii · A. alpestris · A. alpicola · A. alpina (Mountain Rockcress) · A. alpina brevifolia · A. alpina caucasica · A. alpina caucasica 'Corfe Castle' · A. alpina caucasica 'Douler Angevine' · A. alpina caucasica 'Flore Pleno' · A. alpina caucasica 'Gillian Sharman' · A. alpina caucasica 'Goldsplash' · A. alpina caucasica 'La Fraicheur' · A. alpina caucasica 'Little Treasure Deep Rose' · A. alpina caucasica 'Pinkie' · A. alpina caucasica 'Pink Pearl' · A. alpina caucasica 'Pink Sequins' · A. alpina caucasica 'Rosea' · A. alpina caucasica 'Schneehaube' · A. alpina caucasica 'Snowcap' · A. alpina caucasica 'Snowdrop' · A. alpina caucasica 'Snowfix' · A. alpina caucasica 'Snowflake' · A. alpina caucasica 'Snow White' · A. alpina caucasica 'Variegata' · A. alpina caucasica 'White Sequins' · A. alpina crispata · A. alpina 'Revolution' · A. alpina subsp. brevifolia · A. alpina subsp. cantabrica · A. alpina subsp. caucasica · A. alpina subsp. merinoi · A. alpina var. formosana · A. alticola · A. amara · A. ambigua · A. amplexicaulis · A. amurensis · A. anachoretica · A. andicola · A. androsacea (Rock Cress) · A. angulata · A. apennina · A. aprica · A. arabiformis · A. arbuscula · A. arcoidea · A. arcuata · A. arcuata secunda · A. arcuata subvillosa · A. arenaria · A. arendsii · A. arendsii 'Compinkie' (Rock Cress) · A. arenicola (Arctic Rock-Cress) · A. arenicola var. Arenicola · A. arenosa · A. ariana · A. arida · A. armena · A. armerifolia · A. articulata · A. arvensis · A. aspera · A. atriflora · A. atrorubens · A. atrorubens var. atrorubens · A. attenuata · A. aubretioides · A. aubrietioides (Rockcress) · A. aubrietoides · A. aucheri · A. auriculata · A. auriculata parvisiliquosa · A. auriculata subsp. parvisiliquosa · A. austinae · A. austriaca · A. axillaris · A. axilliflora · A. barbarea · A. beckwithii (Beckwith's Rockcress) · A. beirana · A. bellidifolia · A. bellidifolia bellidifolia · A. bellidifolia stellulata · A. bellidifolia subsp. stellulata · A. bellidioides · A. benelocata · A. besseri · A. bijuga · A. billardierei · A. blepharophylla (Coast Rock Cress)

More Info

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Further Reading

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Notes

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Contributors

Data Sources

Accessed through GBIF Data Portal February 02, 2008:

Identifiers

Footnotes

  1. Tai-yien Cheo, Lianli Lu, Guang Yang, Ihsan Al-Shehbaz & Vladimir Dorofeev "Brassicaceae". in Flora of China Vol. 8 Page 1. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
  2. "Arabis". in Flora of China Vol. 8 Page 113. Published by Science Press (Beijing) and Missouri Botanical Garden Press. Online at EFloras.org. [back]
Last Revised: 7/1/2009