1978, Vol. 33, pp. 34-45, O Hippokrates Verlag GmbH
Pla?ta Jwndd ~ e d i rnedlca aant Research
Anatomical Studies on Papaver bracteatum (Lindley) J. W. Fairbairn and E. M. Williamson
Key Word Index: Papaver bracteatum; Laticifers; Papaver somniferurn; Electron Microscopical Studies.
Abstract
The laticifers of P. bracteatum are shown to be similar in distribution and structure to those of P. somniferum; however, they are usually more closely packed and anasto'mose more frequently. Electron microscopy also shows that the alkaloidal vesicles have very similar structure in the two plants, with electron dense caps occurring fairly frequently. A comparison of poppy straw (powdered capsule and stem) from both species show many similarities but that from P. bracteatum can be distinguished by the presence of setae fragments and abundant . lignified parenchyma and sclereids; that from P. somniferum by lignified fragments of the inner epidermis of the pericarp containing nonlignified stomata1 remains. Introduction
The possible economic and medicinal significance of the cultivation of P,brac-
teatum as a source of thebaine on a commercial scale has been widely discussed [ I , 21 since the world consumption of opiates, particularly codeine, is steadily rising without a corresponding increase in the production of opium and poppy straw. Thebaine can be quite readily converted to codeine to meet this demand, and as high-yielding strains of Pi bracteatum have been developed, and the steps of development a t which the yield of thebaine is highest has been determined [2, 3, 41, cultivation may well be economically viable. P. bracteatum is part of the section Oxytona of the genus Papaver (Fa-m. Papaveraceae) and is very closely related to the other two species in the section, which are P. orientale and P. pseudo-orientale; in neither of these two species however does thebaine occur in significant amounts. The morphological characters and chromosome counts of the three species have been described by GOLDBLATT [5] .and differences between the setae and petal colour of P. braceta-
Downloaded by: University of British Columbia. Copyrighted material.
The School of Pharmacy, Department of Pharmacognosy, University of London.
.walXx = Xx are^^ aalaa = la Ialpunq a q e a = qa !ax.xa s1ua3eld = ~d Isa~qywaolqd = jd !ruaolyd = d 'a~nao= a o !ewXlpualad pay!u%!g= .d :slaj -!3!lal = I tsarqy = 3 :d~w!da= 3a !s!wrap!da = a :ewXlpua1lo3 = '1103 :~.to3,= .jea~-SL -a .IOOJu!em 'SJ. '3 'sqnao %u!dolaaap% u ! ~ o qae1ua2r1d s pue 1 1 s a~~ n s d a'SL ~ .g!wa~s'SL *V
Downloaded by: University of British Columbia. Copyrighted material.
l .S?J
F a i r b a i r n , Williamson
latex which i.s particularly abundant in the pedicel and young capsule. However for mechanised harvesting, it is almost certain that the capsule rather than the latex or the leaves will be used. As there seems to be a peak of thebaine content in the fully mature capsules [2, 41, it is probable that this will be the harvested material, especially as the ripe seeds can be separated then and used commercially leaving a 'poppy straw' for extraction of th.ebaine. Our objects in this paper were therefore to study: a) the laticiferous tissues, especially in comparison with those of P. somniferum; b) the microscopical characters of dried capsule and stem so that the straw can be readily identified; c) as ordinary 'poppy straw' from the P. somniferum does not seem to have been described, we have included the microscopic characters of commercial samples for comparison.
Materials and Methods Plants were grown a t our experimental garden in North London, using normal cultivation methods, and the varieties referred to in our earlier publication [4]. The authenticity of the mature plants produced was hedted using the characters given by GOLDBLATT(1974) [5], (1973) [2] and G i j ~ FAIRBAIRN and HAKIM THER and B ~ ~ H(1968) M [6]. I n addition the alkaloid centent was examined and all these varieties were shown to have a high thebaine content. Sections of fresh material were prepared using a freezing microtome and transferred t o a glass dish containing water t o which 1 drop of a saturated solution of Calco-oil Blue in 50°/0 ethanol, slightly
acidified with acetic acid, was added. After standing overnight, the sections were mounted in dilute glycerin; the laticjfers were recognised as their contents had been stained blue-brown. Obviously those cells whose contents had been lost were not stained but they could usually be recognised by their position and highly rcfractive walls. Sections were also prepared for photography by fixing fresh material in 6O/0 gluteraldehyde in 0 . 1 M phosphate buffer (pH 7.0) followed by 1010 osmic acid in the same buffer. Samples were dehydrated in alcohol and left overnight in a 50:50 n~ixture of propylene oxide and araldite, then embedded in araldite. Sections of 1.5 pm thickness were cut and stained with a l o l o Toluidine Blue solution in 1010 borax. Ultra-thin sections (0.08 pm) were also prepared from material fixed in gluteraldehyde, stained with uranyl acetate and lead citrate and examined with an electron microscope.
,
Results
The Laticiferous Tissue. The laticiferous tissue consists of articulated anastomosing vessels occurring only in the phloem of every part of the plant except the ovules and seeds. The distribution and appearance are very similar to that of P. somniferum [7,91 the important points of difference being as follows: Pedicel (Stem).(Fig. 1A). The vascular bundles are arranged in two to three irregular concentric rings in contrast to the regular pattern in P. somniferum. The outer ring consists of numerous smaller bundles adjacent to the ring of lignified parenchyma. Lignification of this ring and of the fibres of the phloem caps increases markedly as
Downloaded by: University of British Columbia. Copyrighted material.
tum and ?elated taxa by GI~NTER and
BOHM [6]. The thebaine is present in the
Anatomic31 Studies on Papaver bracteaturn
an
a r c in the phloem. (s 140).
Fig. 2 B. TS capsulc wall showing branching vascular traccs with anastonlosing laticifcrs
(x 300).
Downloaded by: University of British Columbia. Copyrighted material.
Fig. 2 A. TS main vascular bundle of leaf midrib showing laricifers as
37
Fig. 2 C. TS capsule wall showing fusion of several laticifers 1 = laticifer.
the stem matures. In transverse section the laticifers appear as an arc of closely packed relatively narrow vessels (Fig. 2) in contrast to those of P. somnifevum which are fewer, larger and more isolated from each other. Directly beneath the epidermis and hypodermis, each of which consists of a unicellular layer, are several layers of collenchyma.
Leaf. (Fig. ID).
,
The leaf bundles are similar in structure to those of the stem, with the laticifers appearing in transverse section in the phloem as an arc. (Fig. 2A).
at
an anastomosis (x 600).
Capsule. (Fig. IB). The main bundles, corresponding in position .to the faint longitudinal ridges of the capsule, consist of xylem surrounded by phloem with fibres and groups of sclereids, and give off branch bundles (traces) t o the placentae and to valves (subepidermal regions between the ridges). The placenta traces travel t o the inner epidermis of the placenta where the ovules are developing, but the laticifers do not pass into the ovules. The valve traces branch very frequently forming an extensive network. The traces consist of xylem and phloem, including laticifers, but no fibres o r sclereids.
Downloaded by: University of British Columbia. Copyrighted material.
Fairbairn, Williamson
38
Anatomical Studies on Papaver bracteatum
In the mature root the laticifers occur in small discrete groups in the primary and secondary phloem. They are difficult to distingiush due to the great abundance of starch in the phloem parenchyma.
Electron Microscopical Studies. These showed that the laticifers are very similar to those of P. sornniferurn [8, 10, 111. Abundant alkaloidal vesicles are present together with occasional mitochondria and endoplasmic reticulum (Fig. 3A,B). Some of the vesicles showed the characteristic electron dense caps in some of which a distinct struc-
tured appearance was visible (Fig. 3C). Other vesicles were smooth walled and yet others had the granulated type previously reported (Fig. 3D).
PAPAVER BRACTEATUM STRAW. We have taken the straw to mean the coarsely ground ripe capsule, from which the seeds have been removed, together with the upper part of the pedicel (stem) and therefore the main diagnostic features are based on the microscopy of these parts. However, some seed and leaf material may be present and important microscopical characters of these are included in Fig. 4. The following are the diagnostic fea-
Fig. 3 A. TS of two laticifers from the capsule showing densely packed alkaloidal vesicles (x 4, 500).
Downloaded by: University of British Columbia. Copyrighted material.
Root. (Fig. 1C).
39
Fig. 3 B. More highly magnified laticifers (stem) showing some capped vesicles and endoplasmic reticulum near the periphery (x 13, 500).
tures of the powder in order of importance:
Vascular traces and laticifers. Lignified reticulately thickened vessels show characteristic branching (Fig. 2B; Fig. 4 (2)) and are abundant. f i e y are often found associated with laticifers in fragments of parenchyma; these are the valve and placenta traces of the
capsule. Vessels from the stem vary in abundance depending on the amount of stem present; they have reticulate and annular thickening, may be lignified, but do not show the characteristic branching of the capsule traces.
Setae. These are derived from the stem and leaf, and vary considerably in size,They
Downloaded by: University of British Columbia. Copyrighted material.
Fairbairn, Williamson
40
41
Anatomical Studies on Papaver bracteaturn
Fig. 3
C. Highly magnified vesicle
(stem) showing structured appearance
are multiseriate, with sharply serrate margins. As they are non-lignified, fragments can be readily recognised in preparations stained with phloro-glucino1 and hydrochloric acid (Fig. 4, (8,8a, 8b)).
Sclereids and fibres. The sclereids are lignified, thick-walled and simple pitted, and occur in groups. They vary in size and degree of
of the cap (x 42,
lignification and occur in fragments of tissue from the stem, capsule and leaf. (Fig. 4, ( 4 , l l ) ) .
Laticifers. Because they are thin-walled and therefore easily crushed, they are difficult to observe but can be distinguished by staining with iodine solution after first clearing the preparation with chloral hydrate solution. (Fig. 4, (1)).
Downloaded by: University of British Columbia. Copyrighted material.
-
D. Vesicles (leaf) showing a few granulations on the wall ( x 38,000). [N. B. Magnification quoted above will have to be altered in proporcion to reduction in size ol these photographs when finally printed].
Epicarp and mesocarp.
The epicarp is thin-walled with anomocytic stomata, and is usually found with underlying mesocarp which is thickwalled and unlignified. Fragments of epicarp are rare. (Fig. 4, (7)). Stigma.
Fragments of characteristic lignified
papillae. are. present (Fig. 4, (10)). anc also fragments of the underlying layel of thi&-walled, non-lignified cellr witf granular contenu (Fig. 4 ( 6 ) ) . Pollen
These are fairly abundant and pos sess a warty exine and three pores. (Fig 4, (12)).
Downloaded by: University of British Columbia. Copyrighted material.
Fairbairn, Williamson
42
43
Downloaded by: University of British Columbia. Copyrighted material.
~natomicalStudies on Papaver bracteatum
Fig. 4 P. bracteatwm straw. 1. Fragment of laticiferous tissue; 2. Branching vascular trace from capsule wall; 3. Lignified placenta epidermis; 4. Stone cells; 5. Inner epidermis of pericarp; 6. Thik-walled cells from stigma; 7. Epicarp with underlying mesocarp; 8., 8a and 8b. Fragments of setae; 9. Seed fragment; 10. Papillae from stigma; 11. Fibres; 12. Pollen grains. P. somniferum straw. PS 1. Inner epidermis ofVcapsuleshowing stomata1 remains (st). PS 2. Epidermis of stem showing raised stoma.
Fairbairn, Williamson
44
When present, fragments of seed can be recognised by the deep brown colour and characteristic polygonal reticulum of the testa. Endosperm tissue with oil globules may also be seen. (Fig. 4, (9)).
Leaf. Leaf epidermis is infrequent, and anomocytic stomata are present on the lower surface only and the epidermal cells are smooth and wavy-walled. Starch is very infrequent, the grains are simple. Calcium oxalate is absent.
PAPAVER SOMNIFERUM ( P o p p y Straw) Two commercial samples of straw derived from stem and two derived from capsules were examined, using the techniques already described. The diagnostic features in order of importance were:
Vascular tissue and laticifers.
less areas in fragments stained red with phloroglucinol and hydrochloric acid (Fig. 4, psl).
Outer epidermis of'pericarp. ?fie outer epidermis consists of polygonal, thick-walled, non-lignified cells, with anomocytic stomata, and usually occur adhering to the underlying cells.
Epidermis of placenta. This resembles the inner epidermis of the pericarp and is also lignified with simple pits. However, the cells are smaller with thinner walls and no stomata are visible.
Epidermis of stem. Fragments can be recognised by the elongated cells with numerous raised anomocytic stomata (Fig. 4, ps2); stomata are not visible in P. bracteatum stem because it is so heavily setose.
Characteristic branched valve traces abundant and frequently found in conjunction with laticifers, whore granular contents distinguish them from phloem tissue.
Fibres, Starch and Calcium Oxalate.
Inner epidermis of pericarp.
sent.
Lignified, limp1e pitted groups of fibres occurred infrequently; starch granules simple or up to 6-compound infrequent; calcium oxalate crystals ab-
This consists of elongated, modera- Comparison between P. somniferum and tely thick-walled, lignified cells, with P. bracteatum Straw. many simple pits. The position of the occasional anomocytic stomata, -which The main points of similarity between are probably non-functional in the the two types of straw are as fellows: mature capsule, can be seen as colour- 1. Branching valve traces of the capsule.
Downloaded by: University of British Columbia. Copyrighted material.
Seed.
45
Anatomical Studies on Papaver bracteaturn
Acknowledgements We would like to thank Dr. H. H. BOSMAN of Ver. Pharmaceut. Fabrieken B. V. for supp-lies of commercial poppy straw and Mr. D. MCCARTHY for producing the sections for Fig. 2 and the electron micrograph for Fig. 3.
References 1. United Nations Division of Narcotic Drugs: Scientific Research on Papaver bracteatum. STISOAISER J 1-23, Geneva (1973-76). 2. Fairbairn, J. W. and F. Hakim: J. Pharm. Pharmac. 25, 353-358 (1973). 3. Aynehchi, Y. and S. Jaffarian: Lloydia, 36, 427-8 (1973). 4. Fairbairn, J. W. and K. Helliwell, J. Pharrn. Pharmac., 29, 65-69 (1977). 5. Goldblatt, P.: Ann. Missouri Bot. Gard., 61, 264-296 (1974). 6. Giinther, K-F. and H. Bohm: Ost. Bot. Z., 115, 1-5 (1968). 7. Fairbairn, J. W.and L. D. Kapoor: Planta Med. 8, 50-61 (1960). 8. Thureson-Klein, A.: Annal. Bot. 34, 751-9 (1970). 9. Felklova, M.: Act. Fac. Pharm. Bohem. IX.,7-26 (1964). 10. Didtenson, P. B. and Fairbairn, J. W. Ann. Bot. 39, 707-12 (1975). 11. Nessler, C. L. and Mahlberg, P. G.: Amcr. J. Bot. 64, 541-551 (1977). Address: Prof. Dr. 1, W.Fairbairn, The School of Pharmacy, 29-39, Brunswick Square, London WClN I A X , England
Downloaded by: University of British Columbia. Copyrighted material.
2. Articulated, anastornosing laticifers often associated with vascular fragments. 3. Abundant vessel elements and fibres from the stem. 4. Starch grains few; calcium oxalate crystals absent. They can be distinguished by the following features: 1. Distinctive inner epidermis of pericarp in P. somniferum (Fig. 4 , ~~11. 2. Epidermis from stem of P. somniferum (Fig. 4, ps2). 3. Abundant sclereids and lignified parenchyma in P. bracteatum. 4. Fragments of setae in P. bracteaturn.
Pla?ta Jwndd ~ e d i rnedlca aant Research
Anatomical Studies on Papaver bracteatum (Lindley) J. W. Fairbairn and E. M. Williamson
Key Word Index: Papaver bracteatum; Laticifers; Papaver somniferurn; Electron Microscopical Studies.
Abstract
The laticifers of P. bracteatum are shown to be similar in distribution and structure to those of P. somniferum; however, they are usually more closely packed and anasto'mose more frequently. Electron microscopy also shows that the alkaloidal vesicles have very similar structure in the two plants, with electron dense caps occurring fairly frequently. A comparison of poppy straw (powdered capsule and stem) from both species show many similarities but that from P. bracteatum can be distinguished by the presence of setae fragments and abundant . lignified parenchyma and sclereids; that from P. somniferum by lignified fragments of the inner epidermis of the pericarp containing nonlignified stomata1 remains. Introduction
The possible economic and medicinal significance of the cultivation of P,brac-
teatum as a source of thebaine on a commercial scale has been widely discussed [ I , 21 since the world consumption of opiates, particularly codeine, is steadily rising without a corresponding increase in the production of opium and poppy straw. Thebaine can be quite readily converted to codeine to meet this demand, and as high-yielding strains of Pi bracteatum have been developed, and the steps of development a t which the yield of thebaine is highest has been determined [2, 3, 41, cultivation may well be economically viable. P. bracteatum is part of the section Oxytona of the genus Papaver (Fa-m. Papaveraceae) and is very closely related to the other two species in the section, which are P. orientale and P. pseudo-orientale; in neither of these two species however does thebaine occur in significant amounts. The morphological characters and chromosome counts of the three species have been described by GOLDBLATT [5] .and differences between the setae and petal colour of P. braceta-
Downloaded by: University of British Columbia. Copyrighted material.
The School of Pharmacy, Department of Pharmacognosy, University of London.
.walXx = Xx are^^ aalaa = la Ialpunq a q e a = qa !ax.xa s1ua3eld = ~d Isa~qywaolqd = jd !ruaolyd = d 'a~nao= a o !ewXlpualad pay!u%!g= .d :slaj -!3!lal = I tsarqy = 3 :d~w!da= 3a !s!wrap!da = a :ewXlpua1lo3 = '1103 :~.to3,= .jea~-SL -a .IOOJu!em 'SJ. '3 'sqnao %u!dolaaap% u ! ~ o qae1ua2r1d s pue 1 1 s a~~ n s d a'SL ~ .g!wa~s'SL *V
Downloaded by: University of British Columbia. Copyrighted material.
l .S?J
F a i r b a i r n , Williamson
latex which i.s particularly abundant in the pedicel and young capsule. However for mechanised harvesting, it is almost certain that the capsule rather than the latex or the leaves will be used. As there seems to be a peak of thebaine content in the fully mature capsules [2, 41, it is probable that this will be the harvested material, especially as the ripe seeds can be separated then and used commercially leaving a 'poppy straw' for extraction of th.ebaine. Our objects in this paper were therefore to study: a) the laticiferous tissues, especially in comparison with those of P. somniferum; b) the microscopical characters of dried capsule and stem so that the straw can be readily identified; c) as ordinary 'poppy straw' from the P. somniferum does not seem to have been described, we have included the microscopic characters of commercial samples for comparison.
Materials and Methods Plants were grown a t our experimental garden in North London, using normal cultivation methods, and the varieties referred to in our earlier publication [4]. The authenticity of the mature plants produced was hedted using the characters given by GOLDBLATT(1974) [5], (1973) [2] and G i j ~ FAIRBAIRN and HAKIM THER and B ~ ~ H(1968) M [6]. I n addition the alkaloid centent was examined and all these varieties were shown to have a high thebaine content. Sections of fresh material were prepared using a freezing microtome and transferred t o a glass dish containing water t o which 1 drop of a saturated solution of Calco-oil Blue in 50°/0 ethanol, slightly
acidified with acetic acid, was added. After standing overnight, the sections were mounted in dilute glycerin; the laticjfers were recognised as their contents had been stained blue-brown. Obviously those cells whose contents had been lost were not stained but they could usually be recognised by their position and highly rcfractive walls. Sections were also prepared for photography by fixing fresh material in 6O/0 gluteraldehyde in 0 . 1 M phosphate buffer (pH 7.0) followed by 1010 osmic acid in the same buffer. Samples were dehydrated in alcohol and left overnight in a 50:50 n~ixture of propylene oxide and araldite, then embedded in araldite. Sections of 1.5 pm thickness were cut and stained with a l o l o Toluidine Blue solution in 1010 borax. Ultra-thin sections (0.08 pm) were also prepared from material fixed in gluteraldehyde, stained with uranyl acetate and lead citrate and examined with an electron microscope.
,
Results
The Laticiferous Tissue. The laticiferous tissue consists of articulated anastomosing vessels occurring only in the phloem of every part of the plant except the ovules and seeds. The distribution and appearance are very similar to that of P. somniferum [7,91 the important points of difference being as follows: Pedicel (Stem).(Fig. 1A). The vascular bundles are arranged in two to three irregular concentric rings in contrast to the regular pattern in P. somniferum. The outer ring consists of numerous smaller bundles adjacent to the ring of lignified parenchyma. Lignification of this ring and of the fibres of the phloem caps increases markedly as
Downloaded by: University of British Columbia. Copyrighted material.
tum and ?elated taxa by GI~NTER and
BOHM [6]. The thebaine is present in the
Anatomic31 Studies on Papaver bracteaturn
an
a r c in the phloem. (s 140).
Fig. 2 B. TS capsulc wall showing branching vascular traccs with anastonlosing laticifcrs
(x 300).
Downloaded by: University of British Columbia. Copyrighted material.
Fig. 2 A. TS main vascular bundle of leaf midrib showing laricifers as
37
Fig. 2 C. TS capsule wall showing fusion of several laticifers 1 = laticifer.
the stem matures. In transverse section the laticifers appear as an arc of closely packed relatively narrow vessels (Fig. 2) in contrast to those of P. somnifevum which are fewer, larger and more isolated from each other. Directly beneath the epidermis and hypodermis, each of which consists of a unicellular layer, are several layers of collenchyma.
Leaf. (Fig. ID).
,
The leaf bundles are similar in structure to those of the stem, with the laticifers appearing in transverse section in the phloem as an arc. (Fig. 2A).
at
an anastomosis (x 600).
Capsule. (Fig. IB). The main bundles, corresponding in position .to the faint longitudinal ridges of the capsule, consist of xylem surrounded by phloem with fibres and groups of sclereids, and give off branch bundles (traces) t o the placentae and to valves (subepidermal regions between the ridges). The placenta traces travel t o the inner epidermis of the placenta where the ovules are developing, but the laticifers do not pass into the ovules. The valve traces branch very frequently forming an extensive network. The traces consist of xylem and phloem, including laticifers, but no fibres o r sclereids.
Downloaded by: University of British Columbia. Copyrighted material.
Fairbairn, Williamson
38
Anatomical Studies on Papaver bracteatum
In the mature root the laticifers occur in small discrete groups in the primary and secondary phloem. They are difficult to distingiush due to the great abundance of starch in the phloem parenchyma.
Electron Microscopical Studies. These showed that the laticifers are very similar to those of P. sornniferurn [8, 10, 111. Abundant alkaloidal vesicles are present together with occasional mitochondria and endoplasmic reticulum (Fig. 3A,B). Some of the vesicles showed the characteristic electron dense caps in some of which a distinct struc-
tured appearance was visible (Fig. 3C). Other vesicles were smooth walled and yet others had the granulated type previously reported (Fig. 3D).
PAPAVER BRACTEATUM STRAW. We have taken the straw to mean the coarsely ground ripe capsule, from which the seeds have been removed, together with the upper part of the pedicel (stem) and therefore the main diagnostic features are based on the microscopy of these parts. However, some seed and leaf material may be present and important microscopical characters of these are included in Fig. 4. The following are the diagnostic fea-
Fig. 3 A. TS of two laticifers from the capsule showing densely packed alkaloidal vesicles (x 4, 500).
Downloaded by: University of British Columbia. Copyrighted material.
Root. (Fig. 1C).
39
Fig. 3 B. More highly magnified laticifers (stem) showing some capped vesicles and endoplasmic reticulum near the periphery (x 13, 500).
tures of the powder in order of importance:
Vascular traces and laticifers. Lignified reticulately thickened vessels show characteristic branching (Fig. 2B; Fig. 4 (2)) and are abundant. f i e y are often found associated with laticifers in fragments of parenchyma; these are the valve and placenta traces of the
capsule. Vessels from the stem vary in abundance depending on the amount of stem present; they have reticulate and annular thickening, may be lignified, but do not show the characteristic branching of the capsule traces.
Setae. These are derived from the stem and leaf, and vary considerably in size,They
Downloaded by: University of British Columbia. Copyrighted material.
Fairbairn, Williamson
40
41
Anatomical Studies on Papaver bracteaturn
Fig. 3
C. Highly magnified vesicle
(stem) showing structured appearance
are multiseriate, with sharply serrate margins. As they are non-lignified, fragments can be readily recognised in preparations stained with phloro-glucino1 and hydrochloric acid (Fig. 4, (8,8a, 8b)).
Sclereids and fibres. The sclereids are lignified, thick-walled and simple pitted, and occur in groups. They vary in size and degree of
of the cap (x 42,
lignification and occur in fragments of tissue from the stem, capsule and leaf. (Fig. 4, ( 4 , l l ) ) .
Laticifers. Because they are thin-walled and therefore easily crushed, they are difficult to observe but can be distinguished by staining with iodine solution after first clearing the preparation with chloral hydrate solution. (Fig. 4, (1)).
Downloaded by: University of British Columbia. Copyrighted material.
-
D. Vesicles (leaf) showing a few granulations on the wall ( x 38,000). [N. B. Magnification quoted above will have to be altered in proporcion to reduction in size ol these photographs when finally printed].
Epicarp and mesocarp.
The epicarp is thin-walled with anomocytic stomata, and is usually found with underlying mesocarp which is thickwalled and unlignified. Fragments of epicarp are rare. (Fig. 4, (7)). Stigma.
Fragments of characteristic lignified
papillae. are. present (Fig. 4, (10)). anc also fragments of the underlying layel of thi&-walled, non-lignified cellr witf granular contenu (Fig. 4 ( 6 ) ) . Pollen
These are fairly abundant and pos sess a warty exine and three pores. (Fig 4, (12)).
Downloaded by: University of British Columbia. Copyrighted material.
Fairbairn, Williamson
42
43
Downloaded by: University of British Columbia. Copyrighted material.
~natomicalStudies on Papaver bracteatum
Fig. 4 P. bracteatwm straw. 1. Fragment of laticiferous tissue; 2. Branching vascular trace from capsule wall; 3. Lignified placenta epidermis; 4. Stone cells; 5. Inner epidermis of pericarp; 6. Thik-walled cells from stigma; 7. Epicarp with underlying mesocarp; 8., 8a and 8b. Fragments of setae; 9. Seed fragment; 10. Papillae from stigma; 11. Fibres; 12. Pollen grains. P. somniferum straw. PS 1. Inner epidermis ofVcapsuleshowing stomata1 remains (st). PS 2. Epidermis of stem showing raised stoma.
Fairbairn, Williamson
44
When present, fragments of seed can be recognised by the deep brown colour and characteristic polygonal reticulum of the testa. Endosperm tissue with oil globules may also be seen. (Fig. 4, (9)).
Leaf. Leaf epidermis is infrequent, and anomocytic stomata are present on the lower surface only and the epidermal cells are smooth and wavy-walled. Starch is very infrequent, the grains are simple. Calcium oxalate is absent.
PAPAVER SOMNIFERUM ( P o p p y Straw) Two commercial samples of straw derived from stem and two derived from capsules were examined, using the techniques already described. The diagnostic features in order of importance were:
Vascular tissue and laticifers.
less areas in fragments stained red with phloroglucinol and hydrochloric acid (Fig. 4, psl).
Outer epidermis of'pericarp. ?fie outer epidermis consists of polygonal, thick-walled, non-lignified cells, with anomocytic stomata, and usually occur adhering to the underlying cells.
Epidermis of placenta. This resembles the inner epidermis of the pericarp and is also lignified with simple pits. However, the cells are smaller with thinner walls and no stomata are visible.
Epidermis of stem. Fragments can be recognised by the elongated cells with numerous raised anomocytic stomata (Fig. 4, ps2); stomata are not visible in P. bracteatum stem because it is so heavily setose.
Characteristic branched valve traces abundant and frequently found in conjunction with laticifers, whore granular contents distinguish them from phloem tissue.
Fibres, Starch and Calcium Oxalate.
Inner epidermis of pericarp.
sent.
Lignified, limp1e pitted groups of fibres occurred infrequently; starch granules simple or up to 6-compound infrequent; calcium oxalate crystals ab-
This consists of elongated, modera- Comparison between P. somniferum and tely thick-walled, lignified cells, with P. bracteatum Straw. many simple pits. The position of the occasional anomocytic stomata, -which The main points of similarity between are probably non-functional in the the two types of straw are as fellows: mature capsule, can be seen as colour- 1. Branching valve traces of the capsule.
Downloaded by: University of British Columbia. Copyrighted material.
Seed.
45
Anatomical Studies on Papaver bracteaturn
Acknowledgements We would like to thank Dr. H. H. BOSMAN of Ver. Pharmaceut. Fabrieken B. V. for supp-lies of commercial poppy straw and Mr. D. MCCARTHY for producing the sections for Fig. 2 and the electron micrograph for Fig. 3.
References 1. United Nations Division of Narcotic Drugs: Scientific Research on Papaver bracteatum. STISOAISER J 1-23, Geneva (1973-76). 2. Fairbairn, J. W. and F. Hakim: J. Pharm. Pharmac. 25, 353-358 (1973). 3. Aynehchi, Y. and S. Jaffarian: Lloydia, 36, 427-8 (1973). 4. Fairbairn, J. W. and K. Helliwell, J. Pharrn. Pharmac., 29, 65-69 (1977). 5. Goldblatt, P.: Ann. Missouri Bot. Gard., 61, 264-296 (1974). 6. Giinther, K-F. and H. Bohm: Ost. Bot. Z., 115, 1-5 (1968). 7. Fairbairn, J. W.and L. D. Kapoor: Planta Med. 8, 50-61 (1960). 8. Thureson-Klein, A.: Annal. Bot. 34, 751-9 (1970). 9. Felklova, M.: Act. Fac. Pharm. Bohem. IX.,7-26 (1964). 10. Didtenson, P. B. and Fairbairn, J. W. Ann. Bot. 39, 707-12 (1975). 11. Nessler, C. L. and Mahlberg, P. G.: Amcr. J. Bot. 64, 541-551 (1977). Address: Prof. Dr. 1, W.Fairbairn, The School of Pharmacy, 29-39, Brunswick Square, London WClN I A X , England
Downloaded by: University of British Columbia. Copyrighted material.
2. Articulated, anastornosing laticifers often associated with vascular fragments. 3. Abundant vessel elements and fibres from the stem. 4. Starch grains few; calcium oxalate crystals absent. They can be distinguished by the following features: 1. Distinctive inner epidermis of pericarp in P. somniferum (Fig. 4 , ~~11. 2. Epidermis from stem of P. somniferum (Fig. 4, ps2). 3. Abundant sclereids and lignified parenchyma in P. bracteatum. 4. Fragments of setae in P. bracteaturn.
