Characters Of The Carum Genus

2.3.1. General Description (Tutin et al. 1978)

Leaves 2-4 pinnate, sepals very small or absent. Petals whitish, rarely pink or yellowish, obovate, emarginate. Apex inflexed. Fruit obovoid-oblong, laterally compressed. Ridges filiform, prominent or almost winged. Vittae solitary. Carum genus is involved in the Apioideae subfamily, Apieae tribe and in Seselinae subtribe (Pimenov and Leonov 1993).

It is written in the work of Engler (1964) that the Carum genus comprises about 25 species. Because of the great number of synonyms which usually mean different genera names as well, and the numerous subspecific taxa which are quite different in the works of different taxonomists, we describe only such taxa which can be delimited more or less clearly. Species with the greatest economic importance in the genus, Carum carvi, has been characterized in the next subchapter.

C. multiflorum (Sibth and Sm.) Boiss.

Biennial or perennial up to 70cm. Basal leaves up to 10cm, triangular in outline, 2-3 pinnate. Lobes up to 10mm, ovate to obovate in outline. Rays 5-28, the outer is almost horizontal in fruit. Bracts and bracteoles 4-8, petals white. Fruit 2-3mm, oblong-ellipsoid, ridges very narrowly winged. Distribution: South part of Balkan peninsula, and in SouthEast Italy.

ssp. multiflorum: stems stout, with numerous branches. Rays usually 15-25. In West and South Greece, South Albania.

ssp. strictum (Griseb)tin (syn.: Bunium strictum Griseb, C. lumpeanum Dörfler and Hayek). Stem slender, with few branches. Rays 5-12. Distribution: N.-E. Greece, S.W. Bulgaria, Central and North Albania, S.-E. Italy.

C. verticillatum (L.) Koch, (syn.: Sison verticillatus L., Seseli verticillatum Crantz, Sium verticillatum Lam., Bunium verticillatum Gren and Gosrdon, Pimpinella verticillata Jessen, Apium verticillatum Caruel, Selinum verticillatum E.H.L.Krause, Aethusa fatua Aiton, Meum fatuum Pers).

Erect, glabrous, perennial up to 120cm. Root fleshy, stem striate, little branched, with few small leaves. Basal leaves 10-20cm, usually oblong with more than 20 pairs of segments arranged in whorls. Rays up to 12, the number of linear-acuminate bracts is up to 10. The numerous bracteoles are usually deflexed. Petals white, fruit ellipsoid with prominent ridges. Fruit size is 2.5-4mm. Distribution: W. Europe, in marshes and damp meadows.

C. rigidulum (Viv.) Koch ex DC. (incl.: C. graecum Boiss and Heldr., C. adamovicii Halacsy).

Perennial, glabrous. Stem: erect, simple or with few and long branches and small leaves. Height of the stem is up to 60cm. Basal leaves 10-20cm, oblong, oblong-lanceolate, segments up to 15 pairs. Rays 3—11, erecto-patent. Bracts 0-6, linear. Bracteoles 3-8, linear, lanceolate, acuminate, scarious. Petals white or yellowish-white. Styles longer than stylopodium. The 3-4mm long fruits have prominent ridges. Distribution: In mountains of Balkan peninsula and Central Italy.

C. heldreichii Boiss. (syn.: C. flexuosum (Ten) Nyman, incl.: C. rupestre Boiss and Heldr.). Up to 40cm, perennial. Stems several decumbent, later ascending, flexuous. Basal leaves 3-10cm, oblong-lanceolate, segments up to 8 pairs, the largest near to the base of the lamina. Bracteoles 3-5, linear to setaceous, acuminate, with narrow scarious margin. Petals white or yellowish-white. Styles no longer than stylopodium. Fruit 3.5-4.5mm, ellipsoid, ridges prominent. Distribution: In mountains of Greece, Albania and Italy.

2.3.3. Carum carvi L. (syn.: Carum decussatum Gilib., Carum aromaticum Salisb., Carum officinale S.F.Gray, Apium carvi Crantz, Seseli carvi Lam., Seseli carum Scop., Ligusticum carvi Roth, Sium carvi Bernh., Bunium carvi Bieb., Foeniculum carvi Link, Pimpinella carvi Jessen, Selinum carvi E.H.L.Krause, Karos carvi Nieuwland et Lunell, Sium carum Weber, Aegopodium carum Wibel, Carvi careum Bubani, Pimpinella anisum Meigen et Weniger nec L., Lagoecia cuminoides (Willemet ex DC.)nec. L). Morphology (Tutin et al. 1978, Hegi 1975, Weberling 1981, Filarszky 1911, Corner 1963)

There are annual and biennial forms of Carum carvi (Hornok 1980). There are only very slight and uncertain differences in morphological and anatomical characters between these forms, so in the following we do not distinguish them.

Carum carvi has a taproot system. The main root is about 1cm in diameter, weakly branched. It is whitish or brownish in color.

Stem divaricately branched, glabrous, perennial up to 150cm. Stems striate, leafy (Figure 1). Leaves 2-3 pinnate, lobes 3-25mm, linear lanceolate. The apex of the leaves are slightly dentate. Rays 5-16, unequal. Bracts usually absent, rarely up to 8 and then sometimes 2-3 partite. Bracteoles usually absent.

Flowers are united into an inflorescence forming a compound umbel. Flower is cyclic, with radial symmetry, usually heterochlamydeous, epigynous, pentamerous, tetracyclic. Calyx is reduced in size. Corolla comprises 5 whitish-green petals. Petals are three-lobed in outline, the apex of the central lobe is inflexed. Stamen are haplostemon and episepal, extrorz. Filaments are inflexed in the bud, and became erect only after splitting the anthers.

Carum Carvi
Figure 1 Carum carvi
Floral Diagram
Figure 2 Floral diagram of Carum carvi
Figure 3 Development of the styles of Carum carvi. A: Young flower: anthers splitting, styles small. B: Flower with developing styles.

C: Flower with erect styles. D: Young fruit

Copyright © 1998 OPA (Overseas Publishers Association) N.V. Published by license under the Harwood Academic Publishers imprint, part of The Gordon and Breach Publishing Group.

The gynoecium consists of two carpels (Figure 2). On the top of the ovary and the young fruit there is a well developed discus divided into two more or less hemispherical parts. Styles originate from the upper-central part of the discus. Stigmata are round, with wet surface at the receptive phase.

Flowers are usually hermaphrodite but especially at the second half of the vegetation period and in the lateral smaller umbels there are male flowers too (andromonoecism).

By Carum we can find proterandry-dichogamy. It means, that the anthers ripe and dehisce before the stigma becomes receptive (Figure 3A). The size and the spatial arrangement of the styles change during maturation. At the time of the splitting of the anthers styles are visible as small projections of the two large discus (Figure 3A). In the following step styles are larger, laying on the surface of the discus parallel with each other (Figure 3B). Before the receptive phase of the stigmata, styles become erect (Figure 3C) and at the receptive phase the two styles are standing in V-form. It is visible on the young fruit too (Figure 3D). The styles dry out, turn down and remain on the top of the mericarps after maturation.

The fruit is dry and indehiscent, the type of it is cremocarp. Fruit 3-6mm, ovoid, with special smell. Ridges low, rounded. Each mericarp has five ribs with vascular bundles in them. The mericarps develop from a single carpel of the inferior ovary and separate form one another along the adnation but they remain connected with to the forked carpophore. The origin of the carpophore is not clear. According to the opinion of different anatomists it may arise from flower axis or from the carpels. It seems, that the different areas of the caropohore differ in origin. The basal portion is of receptacular origin while the upper area is carpellary and contains the two ventral vascular bundles of the cremocarp. The abscission zone is in part between the mericarps and between the mericarp and the carpophore. Anatomy (Fahn 1982, Esau 1969, 1977, Johri et al. 1992, Eames and McDaniel 1951, Korsmo 1954) Vegetative organs

Root: The secondary thickened root (Figure 4) is covered by periderm. Cork derived from the phellogen has 4-6 regularly arranged cell layers of quadrangular cells elongated periclinally. Under the phellogen there is a pericyclic parenchyma, the phelloderma ring with numerous parenchyma cells and wide intercellular spaces among them. The pericyclic parenchyma merges almost imperceptibly with the phloem. The small sieve elements and the companion cells are arranged in groups and can be distinguished from parenchyma by their size and darker cytoplasm. In the periphery of the phloem bundle the sieve elements collapse and are almost invisible. There are numerous small oil cavities in the phloem. The epithel cells of these cavities are thin walled and are arranged in one row. The transversally dilatated cells of the phloem rays are filled with large starch grains.

The cambium is practically invisible. The secondary xylem is not delimited with a well defined ring of cambium. The vessels are different in diameter. The vessels are accompanied with parenchyma cells and some xylem fibers. The xylem is divided into sectors by the wide parenchyma rays. The central area of the secondary xylem comprises

Root Secondary Phloem
Figure 4 Secondary root cross section. 1: periderm, 2: phloem, 3: xylem, 4: oil ducts

parenchyma with thin cell walls. In the peripherial ring, near to the cambium, parenchyma of thick lignified walls predominates. In the older (central) area of the secondary xylem there is a dark coloration in some xylem parenchyma cells around vessels. Dark material accumulated inside these vessels too. Such coloration never occurs in the younger secondary xylem.

The primary xylem is excentric in its position and comprises many parenchyma cells. In the primary state the root shows the tissue structure of the typical tetrarch root.

Stem: The young stem is ribbed and has a pith of parenchymatic cells. These cells are broken in the older stem and a pith cavity occurs. Parallel with it, ribs become smaller or almost disappear. The stem is covered with epidermis (Figure 5). The outer tangential wall of the epidermis is thicker and covered by cuticle. Under the epidermis there are collenchyma bundles in the ribs. In older portion of the stem they are visible also in the valleculae. Between the collenchyma bundles, just beneath the epidermis there are 3-4 cell layers of chlorenchyma with cells rich in chloroplasts. Stomata are only in the epidermis above chlorenchyma. Under the stomata there are air chambers in the

Dense Protoplasm
Figure 5 Stem cross section. 1: sclerenchyma bundle, 2: oil duct, 3: phloem, 4: xylem

chlorenchyma. The cells of primary cortex are larger than that of the chlorenchyma. Their diameter is growing towards the vascular tissues. Cortical parenchyma cells are thin walled, almost colorless in their protoplasma, loosely arranged, with large triangular or quadrangular intercellular spaces among them. In the cortex there are schizogenous secretory ducts surrounded by epithel tissue. In the cells of epithel, which are much more smaller than that of the primary cortex, there are large nuclei and dense protoplasma. There are also some idioblasts in the primary cortex filled with crystal sand. In the stem of Carum there is no anatomical delimitation of the primary cortex (starch sheet). The collateral vascular bundles comprise one wavy ring. The vascular bundles are oval in outline. Cambial activity is not high. The secondary vascular tissue can be well distinguished in the xylem: in the secondary part of the xylem the vessels are much more smaller, surrounded and separated by fibers (parenchyma cells with thick lignified walls). The primary part of the bundle comprises vessels of relatively wide diameter. The xylem bundles are separated from each other in this area by parenchyma of thin walls.

The phloem is more or less hemispherical in shape, with weakly developed phloem fiber cap on its peripherial side. In most cases the oil cavities are near to the phloem.

Leaf: The leaf blade is thin, covered by unicellular epidermis. There is considerable difference in the size of the epidermis cells in the adaxial and abaxial surface. The adaxial cells are larger than the abaxial ones. Epidermis is covered by thick cuticle. The ornamentation of the cuticle is wawy-striped (Figure 6). Leaves are bifacial (Figure 7), with one layer of palisade parenchyma and 5-6 layers of spongy parenchyma. Stomata (mesomorf) occur on the both epidermis (amphistomatic type) and at the margin of the

Abaxial Adaxial Epidermis DifferenceAbaxial Side More Stomata Density

leaves. Stomata are anomocytic. The central vascular bundle of the leaves is in a rib. To the adaxial and abaxial side of the collateral vascular bundle there are attached two oil ducts (Figure 7). The adaxial oil duct is smaller, the abaxial one is about twice as large. The epithel cells of the oil cavities show dark coloration. In the vascular bundles the xylem vessels are arranged in one or two rows, in the larger bundles more or less parallel with the leaf surface.

The lateral vascular bundles of the leaves are smaller and are connected only with one oil duct at the abaxial side. Vascular bundles are surrounded by parenchymatic bundle sheath.

The petiole comprises 8 oval, collateral vascular bundles. It is U-shaped in cross section, covered by the epidermis. The rigidity of the petiole is increased by the collenchyma bundles just beneath the epidermis. Generative organs

Flower: The calyx of the Carum flower is very small. It is covered by thin walled epidermis. The mesophyll is homogenous, with a single vascular bundle in central position.

The corolla comprises 5 free petals. Petals are attached to the floral axis with narrow base. The upper epidermis of the petal has papillae with parallel cuticular ornamentation (Figure 8). The mesophyll is homogenous with some vascular bundles.

The stamen have long filaments. The filaments attach the dorsal side of the anthers. The thecas have extrorz opening in the form of a longitudinal split. The endothecium has parallel wall thickenings. The development of the anther wall is dicotyledonous type on the basis of the formation of the middle layer. It means, that in the young anther the

Callose Pollen Mother Cell Cell Wall
Figure 8 Papillae on the petal

hypodermal archesporial cells divides periclinally. The outer cells form the primary parietal layer, the inner one is the primary sporogenous tissue. The primary parietal layer bears two secondary parietal layers. The peripheral one divides into the endothecium, and the middle layer, while the central one is functioning as the tapetum. The type of the tapetum is secretory or glandular. The cytokinesis of the pollen mother cells is simultaneous type. The thick callose wall intrudes centripetally and separates the four microspores only after the second division of the pollen mother cells. Pollen tetrads are tetrahedral, decussate or isobilateral.

The tricolporate pollen grains have bilateral symmerty (Figure 9). At the time of shedding they are at three-celled state.

The gynoecium fused of two carpels. The upper part of the ovary is surrounded by a nectary (discus). On the surface there are numerous nectar stomata sunken below the epidermis with special ornamentation on its cuticle (Figure 10). The styles are covered with axially elongated epidermal cells. The surface of the stigma is spherical, stigmatic papillae does not occur. The type of sitgmata surface is wet.

The ovary has two cavities with 1-1 ovules in them. The ovary wall is parenchymatous. At the apical part of the ovary, at the level of the discus the ovary wall consists of small isodiametric cells (Figure 11). The epidermis and the subepidermal layers are dense in their protoplasts. These cells are involved in the nectar production of the discus. There are oil canals in this area of the ovary too. Canals are associated with vascular bundles, ribs and valleculae can not be distinguished.

The ovule is anatropous. Hypostase differentiates parallel with the archesporial state, obturator develops too. The ovule is suspended from the upper area of the ovary at the

Obturator Pollen
Figure 9 Pollen grain of C. carvi
Ovaries Parts With FigureAloe Vera Anther Tapetum
Figure 11 Cross section of the apical part of the ovary. 1: ovary, 2: sepal, 3: anther
Figure 12 Longitudinal section of the young ovary. 1: discus, 2: ovule, 3: cavity of the ovary

commissural side. The micropyle is situated on the outer and upper part of the anatropous ovule. In young state the ovule does not fill the cavity of the ovary (Figure 12). The single integument is well visible. Figure 12 illustrates, that the abortion of one carpel does not influence the development of the other. After fertilization the ovule is growing intensively in its length and fills the whole cavity of the ovary.

In the cross section of the ovary (Figure 13) it can be detected the body of the nucellus with the embryo sac in it. The embryo sac develops from the hypodermal archesporial cell or from the chalazal cell of the tetrad. The tetrad may be T-shaped. The embryo sac is surrounded by the endothelium (integumentary tapetum), the innermost cell layer of the integument. In the fruit wall there are oil ducts in the valleculae and in the ridges associated with the vascular bundles. In this developmental step these two types of oil ducts are almost the same in diameter.

Around the embryo sac the cell walls of the nucellus disappear, the embryo sac "digests" and absorbs the tissue of the nucellus (Figure 14). The absorbed material is incorporated

Embryo Sac The Ovary
Figure 13 Cross section of the ovary. 1: nucellus, 2: embryo sac, 3: vallecular oil duct, 4: carinal oil duct
Types Vallecula
Figure 14 Developing ovule. 1: embryo sac, 2: vallecular oil duct, 3: carinal oil duct, 4: funiculus
Nucellar Cell
Figure 15 Developing embryo sac, the cellular endosperm emerge. 1: cellular endosperm, 2: digested nucellar tissue, 3: vallecular oil duct, 4: carinal oil duct, 5: funiculus

into the endosperm. The endosperm is nuclear. The first nuclei consist of a group at the micropylar region. Wall formation starts after 64 or more nucleate state. Parallel with this phenomenon, in the fruit wall the areas of the vallecular oil ducts increase. They are much more larger, than ducts in the ribs.

In the following period the embryo sac digests the great portion of the nucellus, and along the wall of the embryo sac emerges the first layer of cellular endosperm. The areas of the vallecular oil ducts are growing (Figure 15). In longitudinal section (Figure 16) we can follow the digestion of the nucellus from the apex of the young seed towards the base. The voluminous nuclear endosperm (nuclei are invisible) is surrounded by the thin layer of cellular endosperm what is broken in the left seed. In this developmental step the upper half of the carpophor has already been splitted.

The diameter of the vallecular oil ducts (and probably the amount of the volatile oils in them) are the largest when the whole endosperm becomes cellular. The central area of the endosperm is digested by the growing embryo (Figure 17). The embryogeny is of the Solanad type. In some cases, besides the small and straight zygotic embryo, development of synergid proembryo can be observed, which is much more smaller than the zygotic one (Figure 18).

Seed and fruit: The seed is endospermic, the embryo is small. A single layer of the epidermis represents the seed coat. The raphe of the seed is ventral. The reserve material of the thick walled endosperm is oil and numerous aleuron grains (Figure 19).

The form of the endosperm in the seed has diagnostic value. By Carum carvi the endosperm is bulging at the area of the raphe in cross section (Figure 20). It means that

Figure 16 Longitudinal section of the young fruit. 1: embryo sac, 2: nucellus, 3: carpophore, 4: style
Germanating Rapa Seeds
Figure 17 Cross section of the young fruit. 1: cellular endosperm, 2: funiculus, 3: vallecular oil duct. 4: carinal oil duct
Cellular Endosperm
Figure 18 Proembryo in the seed. 1: cellular endosperm, 2: proembryo

this species is of the orthospermae type. In other species the surface of the raphe is U-shaped (campylospermae type) or convex (coelospermae type). These characters are used in classification of the Umbelliferae species but they have no phylogenetic importance.

The fruit is schizocarp (cremocarp). The exocarp has small isodiametric cells. The ornamentation of the cuticle is parallelly-striped (Figure 21). There are stomata on the surface of the fruits. The mesocarp is parenchymatous, 8-11 cell layers in thickness. The endocarp (inner epidermis of the fruit wall) is unicellular. It consists of narrow cells with different spatial arrangement (parallel or perpendicular to the transverse axis of the mericarp). The mesocarp of the fruit becomes thin during maturation because of dual purpose: it is drying out, and has been pressed by the great mass of endospermium. The areas of vallecular oil ducts also decrease.

The carpophore splits at maturation as a result of an abscission zone. This zone is a lignified tissue between the two ventral veins (Figure 22).

Fruit Abscission ZoneParenchymatous Mericarp
Figure 20 Cross section of the mature seed. 1: raphe, 2: endosperm, 3: cavity of the embryo with digested endosperm cells, 4: vallecular oil cavity, 5: carinal oil cavity

Figure 22 Schizocarp Subspecific Division and Geographical Distribution of C. carvi

Numerous forms of Carum carvi can be distinguished on the basis of morphological differences, especially on the shape, number, persence or absence of bracts and bracteoles. In the monograph of Hegi (1975) there are the following 10 forms: f. nanum DC., f. demissum Murr, f. coarctatum (Tinant)Baguet, f. latisectum Thellung, f. vulgare Alef, f. intermedium Rouy, f. pterochlaenum DC., f. proliferum Peterm, f. alpinum Schur, f. atrorubens Schube. Soo (1966) describes 9 of the above form, with the exception of f. coarctatum, Carum carvi is distributed especially on different areas of the North hemisphere. It is the species of the natural flora in North and Central Europe, England, East and Central French, South Spain, North Italy, Balkan peninsula, Central Asia. It is spread also as a result of human activity, especially in Holland, North Africa, North America and New Zeland.

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