Caballero B. (ed.) Encyclopaedia of Food Science, Food Technology and Nutrition. Ten-Volume Set

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contain aleurone grains and globules of fixed oil

(Figure 3p).

0064 The odor and taste of the seeds are pleasant and

nut-like. For the collection of the seeds, the capsules

are dried on the plant for about 15 days. After

plucking by hand, these are threshed, and the seeds

are separated and stored.

Sesame

0065 Sesame is the seed of Sesamum indicum L. (Pedalia-

ceae). The seeds are yellowish white, brown, gray to

black, flat pyriform (2.5–3.5 mm by 1.2–2mm by

1 mm), and finely punctate, with four delicate, longi-

tudinal ridges at the edges of the flat faces. The raphe

extends from the hilum at the pointed end as a line

along the center of one flat face to a broader end, and

the scanty endosperm surrounds a large embryo. The

hulled seeds are cream or pearly white in color (Figure

3q and r).

0066 In cross-section, the seed coat consists of an epider-

mis of radially elongated cells (30–60 mm on sides and

45–130 mm at ridges), with thin, cutinized outer

walls; each cell contains a ‘rosette’ calcium oxalate

crystal; the rest of the testa consists of collapsed cells

containing numerous, prismatic calcium oxalate crys-

tals, and the endosperm and cotyledons consist of

polygonal parenchymatous cells containing fixed

oil and small aleurone grains measuring 2–10 mm

(Figure 3s).

0067 The seeds have a faint nutty odor and taste, and

are ripe at the end of about 5 months. The whole

plants are then cut down and made into stooks to

dry, and the seeds are shaken out from the capsules

and stored.

See also: Drying: Theory of Air-drying; Drying Using

Natural Radiation; Sensory Evaluation: Aroma; Taste

Further Reading

Bagchi GD and Srivastava GN (1989) SEM of epicarp

surfaces of some medicinally important Apiaceae.

International Journal of Crude Drug Research 27:

171–177.

Chadha KL and Rethinam P (1994) Advances in Horticul-

ture: Plantation and Spice Crops Part 182, vols. 9–10.

New Delhi: Malhotra Publishing.

Parry JW (1969) Spices, vols. I and II. New York: Chemical

Publishing.

Purseglove JW, Brown EG, Green CL and Robbins SRJ

(1981) Spices, vols. I and II. London: Longman.

Vaughan JG (1970) The Structure and Utilization of Oil

Seeds. London: Chapman & Hall.

Wallis TE (1960) Textbook of Pharmacognosy. London:

Churchill.

Leaf and Floral Structures

G D Bagchi and G N Srivastava, Central Institute of

Medicinal and Aromatic Plants, Lucknow, India

Introduction

0001The aromatic leaves and floral structures of more than

30 plants are commonly used as spices and for

flavoring purposes. Leaves and floral structures have

delicate flavors, and these spices require proper care,

particularly during the drying process. Leaf spices are

also used fresh. The diagnostic morphological and

anatomical characters of the most commonly used

spices are dealt with in detail, along with their

common names, botanical names, family and parts

used. Handling, drying, and storage details are

given wherever available. Other spices, which have

specific, but equally important, uses are summarized

in Table 1.

Chervil

0002Chervil consists of the dried leaves of Anthriscus

cerefolium Hoffm. (Apiaceae). The leaves are decom-

pound and oval, and the leaflets alternate, thin pale

green 2–5  2–4 cm and pinnate; a few hairs occur on

the mid-vein and the margins of leaflets (Figure 1a).

0003In surface view, the lower epidermal cells have

more wavy walls than those on the upper epidermis;

stomata are numerous on the lower epidermis, but

absent on the upper; hairs, usually unicellular and

pointed, are on both surfaces of the main vein and

the margins, but more arise on the lower surface; the

mesophyll consists of a row of palisade cells, 18–

75 16–35 mm in size, followed by spongy paren-

chyma containing vascular bundles; an oil duct is

found below the mid-vein (Figure 1b and c).

0004The odor of chervil somewhat resembles that of

caraway and anise. Leaves, after collection, are then

dehydrated by circulating hot air (50



C) and are then

fragmented mechanically and packed in plastic–lined

bags. (See Drying: Theory of Air-drying.)

Laurel or Sweet Bay

0005The leaves are derived from Laurus nobilis L. (Laur-

aceae). They are lanceolate-acuminate, 10 cm or

more long, coriaceous, pellucid–punctate, and with

revolute, entire margins; the upper surface is glabrous

and shiny, olive green to brown; the lower surface is

dull olive to brown with a prominent mid-rib and

veins (Figure 1d).

SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures 5477

tbl0001 Table 1 Some other commonly used spices from leaf, flower, and flower parts

Botanical name Common name Family Part used Characters

Allium ascalonicum L. Shallot Liliaceae Bulb Bulbs about the size of a nut, white, leaves basal; bulbs

may be taken up and dried or allowed to remain in

the ground and dug up when needed; after lifting,

they are skinned, washed and tied in bunches for

marketing

Allium cepa L. Onion Liliaceae Bulb Bulbs are variable in size: small bulbs are silvery, and

large bulbs are red or yellow in color; bulbs are

harvested when mature, which is indicated by the

tops drooping just above the bulb, while the leaves

are still green; onions are stored in crates, before

storage, they are thoroughly cured

Allium fistulosum L. Leek Liliaceae Leaf Leaves terete and hollow, usually clustered

Allium sativum L. Garlic Liliaceae Bulb Compound bulb, subglobose, has eight to 15 bulblets,

bulblets ovoid, three- to four-sided, covered with

whitish scale leaf which encloses whitish flesh, one

or two translucent scales, in the center, two or three

yellowish to yellowish green leaves present;

harvested when tops turn yellow, exposed to sun for

4–5 days and winnowed; after a fortnight of curing,

they are packed in bags and stored

Allium schoenoprasum L. Chive Liliaceae Leaf Leaves 10–25 cm, terete or grooved above, scape 15–

35 cm; the cut leaves are gathered into bunches of

about 2.5 cm diameter, secured and packed in layers

in trays

Angelica archangelica L. Angelica Apiaceae Leaf and

young stem

Leaves ovate, 30–90 cm, two- to three-pinnate, ultimate

pinnae toothed; leaves cut for drying and freezing in

early summer; the stems should be harvested before

the plant flowers

Cinnamomum tamala

Nees & Eberm

Tejpat (Indian

cassia lignea

leaf)

Lauraceae Leaf Leaves subcoriaceous, opposite, triple nerved rarely

alternate, elliptic oblong, acute base, acuminate,

glabrous, shining, leaves are collected and dried in

sun for 3–4 days and packed in a cylindrical bamboo

nets for marketing

Gaultheria fragrantissima

Wall.

Wintergreen Ericaceae Leaf Leaves alternate, oblong-lanceolate to elliptic

rhomboid, 7–13  2–6 cm, serrate, stiffly coriaceous,

glands dotted

Hyosopus officinalis L. Hyssop Lamiaceae Leaf Leaves sessile, 13  2–8 mm, opposite, linear or

lanceolate, entire, hairy on both surfaces; harvested

just as flowers begin to bloom

Levisticum officinale Koch Lovage Apiaceae Leaf and

flowering

top

Lower leaves large with long petioles, up to three

pinnate, about 70 cm long, uppermost leaves entire

and lanceolate; flowers yellow in stiff umbels; fresh

leaves are generally used; drying of thick leaves

takes 4–5 days

Marrubium vulgare L. Farasiyum Lamiaceae Leaf Leaves opposite, petiolate, downy, oval, up to 5 cm

long, surface wrinkled and has protuberances,

margin dentate; harvested before full flowering and

dried in the shade below 35



Melissa officinalis L. Balm Lamiaceae Leaf Leaves opposite, ovate or triangular; up to 3.5 cm long,

hairy, margin broadly dentate; usually, fresh leaves

are used; for drying, stems are cut and tied in small

bunches and hung in airy space.

Mentha pulegium L. Pennyroyal Lamiaceae Leaf Leaves shortly petioled, up to 1.25 cm long, round to

oval, entire or slightly crenate and pubescent;

leaves are used fresh or in dried form

Murraya koenigii L. Spreng. Curry leaf Rutaceae Leaf Leaves imparipinnate, leaflets nine to 25, ovate-

lanceolate, dentate, acuminate, base oblique,

glabrous above, pubescent beneath, gland dotted;

fresh or shade dried leaves are used

Nepeta cataria L. Catnip Lamiaceae Leaf Leaves ovate, coarsely crenate; harvested when in full

bloom

Continued

5478 SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures

0006 In cross–section, the leaf has a thick cuticle, and the

epidermal cells, in surface view, have sinuous, pitted

and thick walls; the lower epidermal walls are more

curvilinear and distinctly beaded; the lower epidermis

alone bears stomata arranged singly or in pairs; the

mesophyll is differentiated into two layers of palisade

parenchyma, a region of spongy parenchyma contain-

ing scattered spheroidal oil reservoirs, fibrovascular,

and collenchyma tissues; the latter occurs above and

below the vascular bundle of mid-rib, but not in the

veins (Figure 1e–h).

0007 The leaves are characteristically fragrant when

crushed but taste bitter and aromatic. (See Sensory

Evaluation: Aroma; Taste.)

Marjoram (Sweet)

0008 Marjoram consists of dried leaves, with or without

flowering tops, of Majorana hortensis (L.) Moench

(Lamiaceae). The pinnate leaves are obovate to

broadly elliptical, 21 11 mm in size with entire

margins and short petioles; both surfaces are gray–

green, glandular punctate, and pubescent. The floral

parts are: bract – light grayish yellow, obovate, thin,

up to 5.5 3.5 mm; calyx – gamosepalous, about

3 mm long with five prominent teeth; corolla – gamo-

petalous, white to pink or pale lilac, about 3.5 mm

long (Figure 1i).

0009 In a transverse section and/or surface view, it is

possible to see an epidermis with a thin cuticle,

one to two palisade layers and upper and lower

epidermal cells with slightly wavy, knotty, vertical

walls. Glandular and nonglandular hairs occur on

both surfaces, and the latter are uniseriate, two to

five cells in length and more or less bent inwards at

apex; some are papillose. Glandular hairs are of

two types, one with a one- to two-celled stalk and a

one- to two-celled glandular head, the other with

no stalk and a large, eight-celled head; the latter is

sunk in a depression in the epidermis; stomata occur

on the lower epidermis with two ‘neighboring’ cells

(Figure 1j and k).

0010The odor and taste of sweet marjoram are aro-

matic, characteristic, and slightly pungent; the plants

are harvested as soon as they flower. The plants are

cut and tied in bunches and dried in the open air, or

spread on wire trays in ventilated rooms and dried

by circulating warm air. (See Drying: Drying Using

Natural Radiation.)

Mint

0011Mint consists of the dried leaves and flowering tops of

Mentha piperita L. (peppermint) and M. spicata L.

(spearmint) belonging to the family Lamiaceae.

M. piperita is a hybrid between M. spicata and

M. aquatica since M. spicata itself is a hybrid. There-

fore, M. piperita is a triple hybrid. It is an allo-

hexaploid, 2n ¼6x ¼72. However, this species has a

variable chromosome number, which ranges from

2n ¼36 to 2n ¼134 with polyploid and anueploids.

M. spicata (2n ¼48) has originated by hybridization

between M. longifolia and M. suaveolens and

doubling of chromosomes. The resultant polyploid

behaves as allotetraploid. Peppermint leaves are

dark green, about 4.5 2.3 cm, petiolate, ovate and

with serrate margins. The apex is acute and the

midrib prominent, and dot-like oil glands are visible

with a hand lens. Nonglandular hairs are present on

the lower epidermis over the mid-rib and veins at

margins, and a few arise on the mid-rib of the upper

epidermis. Verticillaster inflorescences are usually

arranged in compact, oblong or oval terminal spikes:

calyx – gamosepalous, purplish, about 3 mm long,

glandular punctate and five-toothed; corolla – short,

tubular, light purple and four-cleft; stamens – four;

style with bilobed stigma (Figure 1l). Spearmint

differs from peppermint in having a sharply pointed,

long, narrow spike, an absence of nonglandular hairs

in the upper epidermis, fewer and shorter hairs on the

Botanical name Common name Family Part used Characters

Pimenta racemosa (P. Miller)

J. W. Moore

West Indian bay Myrtaceae Leaf Leaves obovate or elliptic, leathery, shining above;

during harvesting, either leaves are stripped from

the trees or both shoots and leaves are removed and

tied in bundles for drying

Ruta graveolens L. Rue Rutaceae Leaf Leaves alternate, 15 cm long, two to three pinnate,

oblong to spathulate, with many small oil glands;

leaves are usually used fresh

Salvia sclarea L. Clary, clary sage Lamiaceae Leaf Leaves petiolate, opposite, ovate, apex obtuse, base

cordate, crenate margin, thinly hairy above

Tanacetum vulgare L. Tansy Asteraceae Leaf and

flowering

top

Leaves downy, one to two pinnate, margin dentate,

capitula in flat umbels, golden yellow, about 1 cm in

diameter; collected when in flower and dried in the

shade at below 35



Table 1 Continued

SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures 5479

(a)

(d)

(e)

Col

(f)

(g)

(h)

(k)

Pal

Ocl

(b)

(c)

(l)

(n)

(o)

(p)

(m)

(q)

(i)

(j)

fig0001 Figure 1 Spices from leaves and flower tops. Chervil: (a) leaf; (b) cross-section of leaflet through mid-rib; (c) lower epidermis in

surface view. Laurel: (d) leaf; (e) cross-section of leaf through mid-rib; (f) vein; (g) leaf blade; (h) lower epidermis in surface view.

Marjoram: (i) a portion of flowering twig; (j) cross-section of leaf through mid-rib; (k) surface view of lower epidermis; Peppermint: (l)

a portion of flowering twig: (m) cross-section through mid-rib of leaf; (n) surface view of lower epidermis. Origanum: (o) a portion of

flowering twig: (p) cross-section through mid-rib of leaf; (q) lower epidermis in surface view. Reproduced from Spices and Flavoring

(Flavouring) Crops: Leaf and Floral Structures, Encyclopaedia of Food Science, Food Technology and Nutrition, Macrae R, Robinson RK

and Sadler MJ (eds), 1993, Academic Press. Abbreviations: C, calyx; Col, collenchyma; Cor, corolla; Cp, compressed parenchyma; E,

endocarp; F, fiber; Gh, glandular hair; H, hair; Hb, hair base; Hy, hypodermis; Mes, mesophyl; O, ovary; Oc, oil cavity; Ocl, oil cell; Od,

oil duct; P, pericarp; Pal, palisade; Pap, papilla; Pg, pollen grain; Ph, phloem; Pp, pigmented parenchyma; R, receptacle; Rc, reticulate

cells; S, stigma; Sc, stone cells; St, stomata; Sta, stamen; Sty, style; Vb, vascular bundle; Xy, xylem.

5480 SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures

lower surface over the mid-rib, with few, if any, over

the veins, and the absence of crystals in the glandular

hairs.

0012 In cross-section, peppermint leaves show a cuticle

covering both the upper and lower epidermis; upper

epidermal cells having moderately thicker outer walls

than the lower epidermal cells; glandular hairs con-

taining groups of crystals; a mesophyll consisting of a

layer of palisade cells and spongy tissue; between

the upper epidermis and the vascular tissue of the

mid-rib and veins is a conspicuous group of collen-

chyma cells. In the surface view, the cuticle is striated

over the mid-rib, veins and margins, and upper epi-

dermal cells are irregular with wavy walls, except

in the latter regions; numerous small crystals are

present in the cells of upper and lower epidermis

(Figure 1m and n).

0013 Peppermint has a characteristic aromatic odor and

taste, with a cooling sensation on the breath, whereas

the odor and taste of spearmint are characteristic and

aromatic but not followed by a cooling sensation.

Mints are harvested, when in bloom, in bright sunny

weather, by cutting with a sickle 2–3 cm above the

ground. The harvested herb is allowed to dry partially

in the open. Drying is completed by circulating warm

air, which avoids overheating and obviates drying for

too long. After attaining the desired brittleness, the

leaves are stripped from the stem and completely

dried. Afterwards, they are fragmented mechanically

or through wire sieves.

Origanum or Oregano

0014 This consists of the dried leaves and flowering tops of

Origanum vulgare L. (Lamiaceae). The leaves are

light green to greenish brown, with crenate to

crenate–serrate margins and are about 3 cm long

and glandular punctate. The flowers are in spike-

like clusters: bracts – broadly ovate, 2.5–3 2mm

with prominent hairs on the outer surface; calyx –

gamosepalous four-toothed and deeply clefted on two

sides; corolla – 5 mm long, gamopetalous; stamens –

four, epipetalous; style – plumose (Figure 1o).

0015 In surface view and/or transverse section, the

epidermal cells of both surfaces of the leaf are irregu-

lar in shape with uneven and thickened walls; both

surfaces have numerous curved, pointed, unicellular,

nonglandular hairs up to 900 mm long; the surfaces of

some hairs are smooth, whereas many have papillose

surfaces. Uni- to multicellular glandular hairs are

present on both surfaces (Figure 1p and q).

0016 Origanum has a strong camphoraceous odor and

a warm, pungent, bitter, camphoraceous taste. The

plant is collected when in flower and dried in the

shade at less than 35



Parsley

0017Parsley consists of the dried leaves of Carum petros-

elinum Hoffm. (Apiaceae). The leaves are pinnately

compound of three-lobed leaflets; each lobe is divided

into smaller, tooth-like segments that are usually

curly (Figure 2a).

0018The upper and lower epidermal cell walls are, in

surface view, sinuate, and stomata are few in the

upper and numerous in the lower epidermis. In

cross-section, beneath the upper epidermis, the

mesophyll consists of a layer of palisade cells about

40–55 mm long followed by spongy parenchyma;

below the vascular bundle of the mid-rib is an oil

duct (Figure 2b and c).

0019The dried leaves have a characteristic, agreeable,

aromatic odor and taste. Fresh leaves are dried rap-

idly under controlled conditions of heat and air flow

to avoid loss of essential oils, and to preserve a good,

green color. (See Essential Oils: Properties and Uses.)

Rosemary

0020Rosemary consists of the dried leaves of Romarinus

officinalis L. (Lamiaceae). The leaves are about

3.5 cm long and 2–4 mm wide, numerous, opposite

sessile, linear, leathery, entire and slightly glossy with

revolute margins. The upper surface is dark green,

whilst numerous branched trichomes on the lower

surface make it gray and wooly and glandular

punctate with a prominent mid-rib (Figure 2d).

0021In surface view, the cells of the upper epidermis are

polygonal with unevenly thickened and beaded walls,

whilst the lower epidermal cells are larger and thin-

walled. In cross-section, the collenchyma tissue pre-

sent below the upper epidermis forms a thick-walled

hypodermal layer; collenchymatous cells also sur-

round the vascular bundle of mid-rib. One to three

layers of palisade cells are up to about 80 mm in length

and are followed by a zone of spongy parenchyma.

A dense, tangled mass of branched, multicellular,

smooth hairs covers the lower epidermis, and the

tips of the hairs are pointed and curved; glandular

hairs are uni- to multicellular. In the mid-rib vascular

bundle, the vessels are arranged in radial rows (Figure

2e and f).

0022The odor of rosemary is characteristically aro-

matic, having a slight camphoraceous note; the

taste is pungent, aromatic, bitter, and camphorac-

eous. Rosemary is harvested when flowering has

started. At that time, 30–50 cm of the top along

with leaves and flowers are harvested with sickle or

by forage harvester. Care should be taken not to cut

the woody portions of the stem. The first harvest is

obtained approximately 6 months after planting, and

SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures 5481

(a)

(b)

(c)

(d)

(f)

Cor

(g)

(i)

(h)

(j)

(e)

(k)

(i)

Mes

(p)

(r)

(q)

(n)

(m)

Pal

(o)

fig0002 Figure 2 Spices from leaves and flower tops. Parsley: (a) a portion of flowering twig; (b) cross-section leaflet through main vein; (c)

surface view of lower epidermis. Rosemary: (d) a portion of flowering twig; (e) cross-section through mid-rib of leaf; (f) lower

epidermis in surface view. Sage: (g) a portion of flowering twig; (h) cross-section through mid-rib of leaf; (i) cross-section of a portion

of leaf blade; (j) lower epidermis in surface view. Savory: (k) a portion of flowering twig; (l) cross-section through mid-rib of leaf; (m)

cross-section through leaf blade; (n) lower epidermis in surface view. Sweet basil: (o) a portion of flowering twig; (p) cross-section of

leaf through mid-rib; (q) cross-section through side vein; (r) surface view of upper epidermis. Reproduced from Spices and Flavoring

(Flavouring) Crops: Leaf and Floral Structures, Encyclopaedia of Food Science, Food Technology and Nutrition, Macrae R, Robinson RK

and Sadler MJ (eds), 1993, Academic Press. Abbreviations: C, calyx; Col, collenchyma; Cor, corolla; Cp, compressed parenchyma; E,

endocarp; F, fiber; Gh, glandular hair; H, hair; Hb, hair base; Hy, hypodermis; Mes, mesophyl; O, ovary; Oc, oil cavity; Ocl, oil cell; Od,

oil duct; P, pericarp; Pal, palisade; Pap, papilla; Pg, pollen grain; Ph, phloem; Pp, pigmented parenchyma; R, receptacle; Rc, reticulate

cells; S, stigma; Sc, stone cells; St, stomata; Sta, stamen; Sty, style; Vb, vascular bundle; Xy, xylem.

5482 SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures

subsequent harvests can be obtained every 4 months.

Harvested leaves are dried in the shade.

Sage

0023 Sage consists of the dried leaves of Salvia officinalis L.

(Lamiaceae). The leaves are grayish green, oblong–

lanceolate, about 8.5  2.5 cm, petiolate, apex acute,

margins finely crenate, densely pubescent and

glandular punctate with glands obscured by hairs

(Figure 2g).

0024 The upper epidermal cells, in surface view, have

few stomata and straight, beaded walls, whereas the

lower epidermis bears numerous stomata, and the

cells have wavy, beaded walls; numerous nonglandu-

lar and glandular hairs occur on both the surfaces.

The nonglandular hairs are uni- or multicellular, and

the multicellular hairs are more numerous, very long,

narrow pointed and mostly smooth, but some have a

papillose surface; glandular hairs are also uni- or

multicellular. The mid-rib vascular bundle is sur-

rounded by parenchymatous and collenchymatous

cells, and the mesophyll consists of one to three

layers of palisade cells followed by spongy tissues

(Figure 2h–j).

0025 Sage is aromatic in odor and somewhat bitter in

taste. The leaves are gathered for use while the plants

are in flower and are dried in the shade or indoors by

circulating warm air.

Savory

0026 Savory consists of dried leaves and flowering tops of

Satureja hortensis L. (Lamiaceae). The leaves are

green to grayish green, nearly sessile, entire, linear

oblong to spathulate when unfolded, glandular punc-

tate, acute to rounded at the apex, tapering at the

base, 12–35 1–2 mm and pubescent. The flowers

are tubular–bilabiate, purple and up to 5 mm long in

leaf axils; calyx – campanulate, hispid on nerves and

with five subulate teeth; corolla – about 4–5 mm long;

stamens – four and didynamous; style with bilobed

stigma (Figure 2k).

0027 In the surface view, epidermal cell walls of the

upper and lower surfaces are sinuate and beaded;

the stomata are elliptical. The nonglandular hairs

are uniseriate and numerous, with up to six cells

and a pointed, distal cell; the glandular hairs are

numerous and have an up to 12-celled head and

one-celled stalk (Figure 2l–n).

0028 The odor of savory is characteristically aromatic,

and the taste is aromatic and warm. The leaves are

collected when the plants are in flower and are dried

in the shade, or indoors by circulating warm air,

before packaging.

Basil (Sweet)

0029Sweet basil consists of the dried leaves of the Ocimum

basilicum L. (Lamiaceae). The leaves are ovate, tip

acute, petiolate, green, up to 5 cm long and finely

serrate. Hairs arise on the veins, especially on the

underside of the leaf, which is also glandular punctate

(Figure 2o)

0030In surface view, the upper and lower epidermis have

wavy cell walls, and the nonglandular hairs are one- or

multicelled, uniseriate, with pointed apices; the surfaces

of the hairs are finely warty. Glandular hairs have a two-

to four-celled head, and occur on both surfaces but more

on the upper surface. In transverse section, a single

palisade layer lies beneath the upper epidermis, followed

by a zone of spongy parenchyma; the vascular tissue of

the mid-rib and large veins is separated from the upper

and lower epidermis by parenchymatous and collench-

ymatous tissues (Figure 2p–r).

0031The odor of basil is fragrantly aromatic, and the

taste is warmly aromatic and pungent. Fresh leaves

can be dried in the open air but more efficiently

indoors by controlled artificial heat and circulating

air. Dried leaves are fragmented by machines and

graded fine, medium, or coarse before packaging.

Tarragon

0032Tarragon consists of the dried leaves of Artemisia

dracunculus L. (Asteraceae). The leaves are lanceo-

late, entire, sessile, glabrous, and bright green. The

edges of dried leaves curve towards the lower surface,

and are finely revolute, 4 3.5 mm in size (Figure 3a).

0033The cuticle on both surfaces is striated over the

mid-rib and veins. The epidermal cell walls of both

surfaces are undulate; occasionally, small, incon-

spicuous glandular hairs of 35–40 mm diameter are

present on the epidermis. The mesophyll consists of

two rows of palisade cells towards the upper surface

and a single row towards the lower. Below the mid-rib

vascular bundle are a few collenchymatous cells, and

on the upper side, two secretory ducts are present

(Figure 3b and c).

0034The odor and taste of tarragon are agreeable,

aromatic, and like that of anise. The leaves are dried

indoors by artificial heat and circulating air to insure

retention of aroma and color. After being crushed by

machine into particles of a suitable size, the product is

packed in bags and kraft paper.

Thyme

0035Thyme consists of the dried leaves and flowering tops

of Thymus vulgaris L. (Lamiaceae). The leaves are

linear/linear–lanceolate, ovate or oblong, up to

6 0.5–2 mm, apex acute, base obtuse tapering into

SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures 5483

(a)

(b)

(d)

(e)

(c)

(f)

(g)

(h)

Sty-

(n)

(o)

(r)

(p)

(m)

Sta

Sty

Cor

(q)

(k)

(j)

(i)

Pap

(l)

fig0003 Figure 3 Spices from leaves, flower tops and flowering parts. Tarragon: (a) a portion of flowering top; (b) surface view of upper

epidermis; (c) cross-section of leaf through mid-rib. Thyme: (d) a portion of flowering twig: (e) surface view of lower epidermis;

(f) cross-section of leaf blade. Cassia bud: (g) bud; (h) longitudinal section through bud. Clove: (i,k) whole clove; (j) same viewed from

above; (l) longitudinal section of same; (m) transverse section through the receptacle; Saffron: (n) style with three stigmas: (o) a

stigma; (p) same showing vascular supply; (q) transverse section through lower portion of stigma; (r) upper end of stigma showing

papillae and pollen grain. Reproduced from Spices and Flavoring (Flavouring) Crops: Leaf and Floral Structures, Encyclopaedia of Food

Science, Food Technology and Nutrition, Macrae R, Robinson RK and Sadler MJ (eds), 1993, Academic Press. Abbreviations: C, calyx;

Col, collenchyma; Cor, corolla; Cp, compressed parenchyma; E, endocarp; F, fiber; Gh, glandular hair; H, hair; Hb, hair base; Hy,

hypodermis; Mes, mesophyl; O, ovary; Oc, oil cavity; Ocl, oil cell; Od, oil duct; P, pericarp; Pal, palisade; Pap, papilla; Pg, pollen grain;

Ph, phloem; Pp, pigmented parenchyma; R, receptacle; Rc, reticulate cells; S, stigma; Sc, stone cells; St, stomata; Sta, stamen; Sty,

style; Vb, vascular bundle; Xy, xylem.

5484 SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures

a petiole and with revolute margins. The upper surface

is light gray or light brownish gray to weak olive green

with numerous hairs; the lower surface is grayish, pu-

bescent, and glandular punctuate. About 12 flowers

arise in axillary whorls: calyx – tubular, bilabiate,

about 4 mm in length, pubescent, nine to 12-nerved

with the upper lip three-toothed; the lower lip has two

hairy, ascending, attenuate divisions, and the throat is

hairy; the corolla is about twice as long as the calyx,

purplish and bilabiate; the stamens are four and didy-

namous, style with bi-lobed stigma (Figure 3d).

0036 The epidermis of both leaf surfaces in the surface

view shows wavy walls and numerous nonglandular

and glandular hairs; the nonglandular hairs are uni- or

multicellular with papillose walls, and are stiff and

pointed. The glandular hairs are of two types: one

with a short stalk and unicellular head, and the other

with an eight- to 12-celled head, which measures up to

18 mm in diameter, and no stalk. In cross-section, the

mesophyll consists of one or two layers of palisade

cells, variable in size, followed by spongy tissues;

the vascular bundle of the mid-rib has numerous fibers;

thelamina contains two tothree smallvascular bundles

on both sides of the mid-rib (Figure 3e and f).

0037 Thyme has a fragrant and aromatic odor when

crushed, and the taste is aromatic, warm, and pun-

gent. About 15 cm from the tops of the plants is

harvested, when in bloom, and the clipped stems are

dried in the sun or in well-ventilated shed or room.

Cassia Buds

0038 Cassia buds consist of the dried flowers of Cinnamo-

mum cassia Blume (Lauraceae) gathered shortly after

opening. They are dark brown, club, urn- or top-

shaped bodies, enclosed within a grayish brown,

cup-shaped calyx with a dome-like visible top of the

pericarp. The calyx tube is rough and hard, and fre-

quently has the pedicel attached; the exposed pericarp

is smooth and lustrous with the small protuberant

base of the style visible (Figure 3g and h).

0039 In longitudinal section, the cortex of the calyx con-

tains parenchyma cells up to 75 mm long, secretion

cells up to 66 mm long and stone cells up to 80 mm

long. The pericarp consists of a sclerenchymatous epi-

carp about 45–58 mm in radial thickness; the paren-

chymatous mesocarp contains prismatic calcium

oxalate crystals, stone cells, secretion cells, and vascu-

lar tissues. The endocarp sclerenchymatous cells of the

ovary canal are thick-walled and without a lumen,

whilst the cells of the remaining region are rectangular,

moderately thick-walled, and contain large prismatic

crystals of calcium oxalate (Figure 3h).

0040 Cassia buds have a cinnamon-like odor and a

sweet, warm pungent taste akin to that of cassia bark.

Cloves

0041Cloves are dried flower buds of Syzygium aromati-

cum (L.) Merril & Perry (Myrtaceae). Cloves are like

small, round-headed nails, about 10–17.5 mm long

and blackish brown in color. The stalk consists of

a cylindrical hypanthium, above which is a bilo-

cular ovary containing numerous ovules on axile pla-

centae; the ‘head’ consists of four, slightly projecting,

calyx teeth, four membranous petals and nume-

rous incurved stamens surrounding a large style

(Figure 3i–l).

0042In transverse section, the hypanthium (receptacle),

cut below the ovary, shows an epidermis with a thick

cuticle and numerous, scattered, ranunculaceous

stomata on the surface. The outer cortex contains two

or three rows of large, ovoid to elliptical oil reservoirs

(up to 200 mm in length) lined by a secretory epithelium

and embedded in parenchyma; beneath is a zone con-

sisting of an interrupted circle of bicollateral, fibrovas-

cular bundles accompanied by a few sclerenchyma

fibers and crystal fibers containing rosette calcium ox-

alate crystals. The bundles are embedded in parenchy-

matous cells with sinuate walls, and beneath these is a

zone of parenchyma, in which some cells possess

thickened angles and wavy walls, whereas others

form chains around intercellular air spaces. Next is a

zone of small-celled parenchyma followed by a second

or inner zone of fibrovascular bundles, along with a

few thick-walled, pericyclic fibers (Figure 3m).

0043The sepals have an epidermis similar to the

hypanthium, with numerous stomata on the outer

surface, a mesophyl with a few slender, vascular

strands and numerous, ovoid oil glands and rosette

crystals of calcium oxalate. The petals have straight-

walled epidermal cells, an undifferentiated mesophyll

containing oil glands, rosette calcium oxalate crys-

tals, and small vascular strands. The filament of the

stamen bears oil glands beneath the epidermis, and

the connectives bear a large oil gland at the apex.

0044Cloves have a strong, pungent and spicy odor and a

pungent, aromatic taste. Cloves are propagated by

seeds. Hulled washed seeds produce better seedlings

than unhulled fruits. The seeds are planted in shaded

nurseries, and seedlings are raised. Shade and wind

breaks are necessary in the early stages of growth.

Trees begin to flower at about 4–5 years and continue

to produce until 70 years of age. The crimson buds

are picked before the corolla expands and are evenly

spread under the sun on a concrete floor or on mats

and gently stirred to bring about uniform drying. In

good weather, drying is completed in 4–7 days. Quick

drying produces the best-quality spice. Some cloves

are dried on zinc sheets or in kilns. Cloves are apt to

absorb moisture if, while drying, they are left in the

SPICES AND FLAVORING (FLAVOURING) CROPS/Leaf and Floral Structures 5485

open overnight. The average annual yield of dried

cloves per tree is about 3 kg but yields of 18 kg or

more per tree are also not uncommon. Finally, they

are packed in sacks known as ‘mats’ made of coconut

leaves and stored in a dry room. Prolonged storage

may cause a loss of volatile oils.

Saffron

0045 Saffron is made from the dried stigmas of Crocus

sativus L. (Iridaceae). The three stigmas are attached

to the top of the style, and are 25 mm long, cornuco-

pia-shaped, dark red and with fimbriate margins.

The styles are about 10 mm long, cylindrical,

solid and yellowish brown to pale yellowish orange

(Figure 3n–p).

0046 The stigma consists of thin-walled parenchyma

containing coloring matter and covered by a thin-

walled epidermis. The distal end of the stigma

shows numerous bladder-like, cylindrical papillae

up to 150 mm in length, among which occur a few

smooth, spherical, pollen grains from 40 to 120 mmin

diameter (Figure 3q–r).

0047 The odor of saffron is strong and characteristically

aromatic, and the taste is bitter/aromatic. The flowers

are collected every morning, as they open, and the

stigmas are then collected, either by pulling them out

or cutting them off with the fingernails, after which

the flowers are discarded. The value of saffron

depends heavily on the methods by which the stigmas

are processed. The stigmas are placed in sieves in

layers 2–3 cm thick. These sieves are placed 15 cm

above an almost spent fire for drying. By stacking

them and by changing their order or position, the

product is carefully dried. Stigmas are protected

against dampness as well as light, because light

bleaches saffron to a dull yellow color. Saffron should

be preserved in amber-colored bottles or tin boxes.

See also: Drying: Theory of Air-drying; Drying Using

Natural Radiation; Essential Fatty Acids; Sensory

Evaluation: Aroma; Taste