Potpourri as a Sustainable Plant Product: Identity, Origin, and Conservation Status.
While displays of decorative dried plant material are popular in homes
in Europe and North America, knowledge regarding potpourri ingredients
is limited. This study examined the identity, diversity, origin,
economic sources, and sustainability of such ingredients used in the
United Kingdom (UK). Research at the Royal Botanic Gardens, Kew,
commencing in 1990 and involving 1,000 samples of individual potpourri
ingredients from 12 UK manufacturers and traders, revealed 546 different
ingredients, representing up to 455 species, 289 genera, and over 100
families. Despite the wide taxonomic spread, several distinct plant
part–family groups contributed the most potpourri ingredients: i.e.,
fruits from Arecaceae, Fabaceae, Malvaceae, Pinaceae, Poaceae, and
Rutaceae; seeds from Fabaceae; leaves from Arecaceae, Fabaceae, and
Poaceae; inflorescences from Asteraceae; as well as stems from cane,
pith, timber, and pole wood. The vast majority of ingredients imported
from Asia, especially India, were byproducts from crops and wild
harvested species used by the Indian herbal healthcare industry. Global
conservation assessments are lacking for 80% of wild collected Indian
potpourri species, and those that have assessments are mainly abundant
and widespread in ruderal or wetland habitats and of Least Concern (IUCN
2013), except Pterocarpus marsupium and P. indicus (Fabaceae), which are vulnerable globally, and Calamus andamanicus (Arecaceae) and Oroxylum indicum
(Bignoniaceae), which are vulnerable nationally within India. A further
eight, primarily medicinally traded species, are regarded as threatened
within individual Indian states. Additional unique potpourri
ingredients were sourced from Thailand, but only about one-tenth of
study samples were from Africa, Middle East, Europe, America, and
Australia. Temporal studies of potpourri ingredients could reflect
changes in the use and abundance of species in other trades such as
medicines, food, and materials.
Key Words
Non-timber forest products United Kingdom India Thailand plant families plant parts wild collected crops conservation status Indian herbal healthcare industry ethnobotany
Introduction
Potpourri
(a mixture of dried plant materials displayed in bowls in homes for
decoration, color, and fragrance) has a history in Europe and North
America dating back to at least the mid-18th century.
Traditionally, fragrances and colors were inherent in locally gathered
materials, e.g., lavender flowers and rose petals (Black and Dann 1989).
Since the 1990s, many commercial potpourri packs sold in the United
Kingdom (UK) contain imported ingredients that originate (almost
entirely) from the tropics and include non-floral plant materials,
algae, fungi, and lichens, to which manufactured dyes and fragrances are
added. Despite significant visibility within trade, estimated at 600
tons and GBP 50 million per year (Hastings 2001), exotic plant materials used in UK potpourri are understudied, except for one study of palm ingredients (Cook 2007). Tucker et al. (2010)
indicated that almost anything that is botanical, structurally
interesting, and/or inexpensive, such as lawn sweepings and waste
products from other industries, can be included in modern potpourri.
This current study considers the following questions: are exotic
potpourri ingredients likely to exhibit particular botanical
characteristics, be from distinct geographical regions, or represent
wastes from specific economic sectors? Furthermore, are supplies
sustainable, and do they originate from crops or wild collected species?
Ultimately, can potpourri studies indicate likely over-collected
species to target for future conservation studies?
Since
1990 the Royal Botanic Gardens, Kew, has worked with 12 companies to
help inform their selection of safe and sustainable materials for
potpourri sold in the UK. Kew’s resultant collection of potpourri
samples, reflecting the diversity of plant ingredients traded, were
studied in an attempt to answer some of the above research questions
with respect to the UK market.
Methods
Morphological Identification of Potpourri Ingredients
Over
a period of 20 years, a large collection of 1,000 individual potpourri
ingredient samples received from manufacturers was accessioned in Kew’s
Economic Botany Collection (accession numbers PP 1–1017). It was
possible to identify the majority of samples to species, to assign
families (those for angiosperms follow Haston et al. [2009]),
and to determine plant parts used. Potpourri manufacturers provided
additional data including geographical sources (58% of samples) and
suggested Latin scientific names (33%).
Identification
of potpourri trade samples is challenging as most are incomplete
botanical specimens (usually based on one plant part or fraction) and
frequently altered in a variety of ways, including bleaching, coloring,
and reshaping. Ingredient traceability and voucher herbarium specimens
for potpourri trade ingredients are not available, so identifications in
this paper are mainly based on finished ingredients only.
The
majority of samples were identified by morphological comparison to
botanical items in Kew’s scientific collections (including herbarium,
carpological, economic botany, and anatomical), often with help from
specialist taxonomists and photographic publications on modern dried
floristry materials that include some potpourri species (Rohrer 1984; Sprunger 2003; Sprunger and Wieler 1992; Tucker et al. 2010).
For more difficult samples, identification was sometimes confirmed by
anatomical analysis, but usually more complete specimens were requested
from suppliers. Unfortunately, these were often still inadequate,
infertile specimens, but as they were preprocessed, extra features
sometimes aided identification.
Primary Uses and Conservation Status
Sustainability
issues relating to potpourri species from India (the major source
country for UK-traded potpourri) were studied. From literature reports,
primary uses for Indian potpourri species were researched and it was
determined whether these were crops or wild species. Here the term
“crop” includes farm forestry, plantation, and ornamental species as
well as agricultural crops. Unfortunately the literature sometimes uses
“wild collected” loosely to include harvests from introduced and
naturalized species, and even extends to harvests of non-wood parts such
as fruits and leaves from plantation timber species or ornamentals.
However, conservation assessments are only pertinent to wild, native
species and not to crops. References consulted regarding native and
introduced status of Indian species include Dixit (c. 1984), Karthikeyan et al. (2009), Singh et al. (2000), and Ved and Goraya (2008).
Conservation status of wild collected Indian-sourced potpourri species
at global, Indian national, and regional levels was collated with
reference to the IUCN Red List 2013.2 (IUCN 2013), Rao et al. (2003), Ravikumar and Ved (2000), and various CAMP workshops (ENVIS–FRLHT 2012).
A detailed Red Data List with assessments for the whole Indian flora is
lacking, but the above sources identify obviously threatened species.
Results and Discussion
Of
the 1,000 potpourri samples studied in Kew’s Economic Botany
Collection, 899 were identified to genus or species and 2 were
identified to tribe. A further 99 were not identifiable but were
classified into 71 separate ingredients. Overall the samples included
546 unique potpourri ingredients, representing a minimum of 430 and a
maximum of 455 different species and at least 289 genera and 100
families. (Note: more than one potpourri ingredient can occur per
species, representing use of different plant parts.)
Of
the 331 Latin scientific names supplied by industry, at least 46 were
incorrect. Mistakes were not only at the species level, but the supplied
genus name was incorrect in 33 cases, and for 13 the suggested genus
was from a different plant family to the identified family of the
sample. Furthermore, names supplied by industry were often incorrectly
spelled. However, use by exporters of local botanical expertise to label
plant ingredients with Latin scientific names is a positive step.
Taxonomic Groups
The
vast majority of potpourri ingredients in this study (492) were
angiosperms, 28 were gymnosperms, and a few were ferns (8), fungi (8),
lichens (5), bryophytes (4), and algae (1). Around one-half (51%) of
ingredients were from just 9 plant families, and 73% were from just 22
(see Fig. 1). The remaining 78 families were represented sparsely, with only 1 or 2 ingredients in each.
Fig. 1
The
22 most frequently represented families in UK potpourri (out of the 100
identified) that account for 73% of potpourri ingredients in this
study.
Plant Parts
The frequency of potpourri ingredients classed by plant parts are shown in Fig. 2.
Several distinct, plant part–family groups (e.g., Fabaceae fruits)
contributed much more to potpourri than others; these are discussed
below.
Fig. 2
Plant parts represented in UK potpourri ingredients.
Infructescence, Fruits, and Fruit Parts
Nearly
half of all potpourri ingredients were fruit related, and about
one-quarter related to fruits from 7 families: Fabaceae, Malvaceae,
Arecaceae, Pinaceae, Poaceae, Rutaceae, and Cucurbitaceae.
Empty
fruits, follicles, and valves (byproducts from extraction of seeds or
fruit pulp for various uses) serve as robust bulking materials that can
survive the potpourri production mixing process. Acacia auriculiformis A. Cunn. ex Benth. (Fabaceae) and Gossypium (Malvaceae) were particularly frequent and well regarded for this, but others included Leucaena leucocephala (Lam.) de Wit (Fabaceae), Ceiba pentandra (L.) Gaertn., and Sterculia (Malvaceae). Terminal parts of female cones and separated seed scales of Cedrus (Pinaceae) serve a similar purpose. Fragments (endocarp, mesocarp, or perianth) from fruits of Cocos nucifera L., Areca catechu L., and Borassus flabellifer
L. (Arecaceae) are similarly robust and, additionally, are utilized as
absorbers of fragrances and dyes in potpourri mixes. More unusual fruit
byproducts included the fibrous vascular network from Luffa spp. (Cucurbitaceae) and fruit vein tissue and stalk from Tamarindus indica L. (Fabaceae).
Whole
fruit potpourri ingredients serve a more decorative purpose and are
often hand-placed as eye-catching “toppers” within mixes. Examples
include cones from Picea, Pinus, Larix, and Tsuga (Pinaceae), cone-like fruits and/or fruiting branches of Calamus, Daemonorops, Phoenix sylvestris (L.) Roxb., Mauritia flexuosa L.f., Raphia and Trachycarpus (Arecaceae), cereal infructescences of Avena, Echinochloa, Pennisetum, Setaria, Sorghum bicolor (L.) Moench, Triticum, and Zea mays L. (Poaceae), winged fruits of Pterocarpus spp. (Fabaceae), dried, fleshy fruit slices of Citrus spp. and Aegle marmelos (L.) Corrêa (Rutaceae), and even entire or sliced gourds and pumpkins, Cucurbita pepo L. and Lagenaria siceraria (Molina) Standl. (Cucurbitaceae).
Leafy Stems, Leaves, or Leaf Parts
Although
leaves are sought-after potpourri ingredients providing contrasts of
shape and color, manufacturers often expressed difficulties in sourcing
these. Ingredients in this study included leaves and leaflets (64),
leafy stems (25) and skeleton leaves, husks, and sheaths (6) sourced
from 34 families, with 54% from eight: Arecaceae, Fabaceae, Poaceae,
Asparagaceae, Myrtaceae, Pinaceae, Moraceae, and Adiantaceae. The most
popular leaf sources were Borassus flabellifer (14 samples) and Samanea saman (Jacq.) Merr. (12).
Inflorescences, Flowers. and Flower Parts
Relative
to fruit-based ingredients, floral elements in potpourri were less
significant. In all, 24 families contributed 77 floral ingredients, but
42% were sourced from the Asteraceae, from genera with established value
in the wider decorative dried floristry industry including Bracteantha (strawflowers), Tagetes (marigolds), Sphaeranthus (globe flowers), and Zinnia (zinnias).
Seeds
Of 43 seed potpourri ingredients, the majority (21) were sourced from Fabaceae, notably commercial peas and beans: Lens, Phaseolus, Pisum, Trigonella, Vicia, and Vigna. Samples were usually loose seeds but, for Trigonella foenum-graecum L. and Vigna radiata
(L.) R. Wilczek, seeds were stuck on plastic balls to form decorative
“toppers” which provide bulk in potpourri packs. Seeds from Brassicaceae
(Brassica juncea (L.) Czern.), Pedaliaceae (Sesamum indicum L.), and mericarps of Apiaceae (Cuminum cyminum L. and Foeniculum vulgare Mill.) were used similarly.
Others
Other (non-seed) spherical toppers occurred, including whole fruit-rinds of Aegle and Limonia (Rutaceae), thin slices of Aeschynomene aspera L. pith (shola or sola) glued onto plastic balls, woven fruit valves of Leucaena leucocephala,
and woven leafless stems from climbing plants generally known as latas
in India. Lata stems are woven into other shapes too and are frequent in
potpourri catalogues (e.g., Global Dried Flowers n.d.). The slender, wiry branches of Finlaysonia obovata Wall., a non-timber forest product (NTFP) used for baskets, fishing nets, binding, and tying (Nair 2000),
is one possibility; however, identifications of leafless-stem items in
this study were not confirmed and many species may be used. Sola pith
items also varied from short remnant lengths of pith, to small
artificial flowers and ornaments, to the covered balls described above.
These probably originate from the craft industry in West Bengal, India,
which produces ornaments, models, toys, and headgear from pith (CSIR 1985–1988).
The most common bark ingredients were identified as the inner bark of Cinnamomum species and Carica papaya L., and, regarding algae, bryophytes, fungi, and lichens, most frequent were fruiting bodies of the fungi Microporus xanthopus (Fr.) Kuntze and Daedalea quercina (L.) Pers., and the lichen Cladonia.
Geographical Origin
Figure 3
shows at least 48% of the UK potpourri samples in this study were
sourced from Asia compared to 10% from outside Asia. Furthermore, this
Asian percentage is likely to be a considerable underestimate as
identifications of samples with unrecorded origins concurred more
frequently with Indian or Thai species than those from other regions.
Details of regional patterns are summarized below.
Fig. 3
Region of origin of 1,000 potpourri samples (country origins given for Asia).
Asia
The
vast majority of the 482 Asian potpourri samples in this study were
from India (77–82%) and Thailand (16–22%), with the remaining 1% shared
between Indonesia, Pakistan, and China. At least 145 potpourri taxa were
recorded from India and up to 73 from Thailand. While many Thai-sourced
taxa were also sourced from India, 32 were uniquely sourced from
Thailand. The majority of Thai ingredients were accessioned post-2002,
when some of UK’s potpourri manufacturing relocated to Thailand.
Thailand imports ingredients from India for this, but evidence suggests
more local ingredients are sought too. Barleria strigosa Willd., Camchaya sp., Congea tomentosa Roxb., Daemonorops jenkinsiana (Griff.) Mart., Durio zibethinus L., Hibiscus sabdariffa L., Lagerstroemia speciosa Pers., Neohouzeaua mekongensis A. Camus, Neuracanthus tetragonostachys Nees, Phoenix sp., possibly P. loureiroi Kunth and Rumohra adiantiformis (G. Forst.) Ching are examples of such potpourri ingredients sourced from Thailand only.
There
is little doubt that the majority of UK potpourri ingredients
originating from India derive mainly from byproducts, surpluses, and
rejects of materials used by the Indian herbal healthcare industry
(IHHI). The IHHI produces human and veterinary herbal medicines of
single and multispecies drug formulations, as well as hair, skin, and
oral care products such as shampoos, toothpastes, and cosmetics, and
also nutraceuticals. Four main sources (see Table 1) include:
Table 1
Scientific
and common names (not trade names) for species of UK potpourri
ingredients exported from India, grouped by the economic sectors that
are probable sources. Species listed in the left-hand column are wild
collected, those in right-hand column are crops, and the center column
lists species which occur both as wild collected and as crops. Crops
include Indian agricultural crops and farm forestry, plantation, and
ornamental species; crops imported into India are indicated with * and
country of origin is provided. Dept. of AYUSH, India (1999–2011;2007–2009;2008–2011) and Indian Council of Medical Research (2003–2014) were referred to for lists of Indian herbal pharmacopoeia species.
WILD COLLECTED
CROPS/WILD COLLECTED
CROPS
A. INDIAN HERBAL HEALTHCARE INDUSTRY SPECIES
1. Species used for commercial pharmaceutical extracts (see Appendix in Khare 2007)
Lycopodium sp. (club moss)Reissantia sp.
Ammi visnaga (L.) Lam. (khella)
Capsicum annuum L. Longum group (chilli pepper)
Pimenta dioica (L.) Merr. (allspice)
2. Indian herbal pharmacopoeia (Ayurveda, Siddha, and Unani) species and genera
Boswellia serrata Roxb. ex Colebr. (Indian frankincense)
Butea monosperma (Lam.) Taub. (bastard teak)
Calamus sp. (rattan)
Cedrus deodara (Roxb. ex Lamb.) G.Don (deodar)
Helicteres isora L. (Indian screw tree)
Oroxylum indicum (L.) Kurz (midnight horror)
Pterocarpus sp. likely includes P. marsupium Roxb. (Indian kino tree)
Sphaeranthus indicus L. (East Indian globe thistle)
Sterculia sp. possibly S. urens Roxb. (karaya)
Strychnos nux-vomica L. (nux vomica)
Aegle marmelos (L.) Corrêa (bael, Bengal quince)
Bombax ceiba L. (silk cotton tree)
Borassus flabellifer L. (palmyra palm)
Calophyllum sp. likely C. inophyllum L. (Alexandrian laurel)
Species used in the manufacture of standardized pharmaceutical extracts (Khare 2007), including Ammi visnaga (L.) Lam. for amiodarone, nifedipene, and cromolyn, Capsicum annuum L. for capsaicin, Pimenta dioica (L.) Merr. for eugenol, Reissantia for pristimerin, and also Lycopodium spores used in pharmaceutical products;
2)
Species listed in the official herbal pharmacopoeias of India for Ayurveda, Unani, and Siddha (Dept. of AYUSH, India 1999–2011, 2007–2009, and 2008–2011, and Indian Council of Medical Research, 2003–2014);
3)
Close relatives, confused species, substitutes, and alternatives to pharmacopoeia species;
4)
Additional species recorded to be sold in Indian medicinal plant markets by Ved and Goraya (2008),
including medicinal herbs and plants used for oils, gums, waxes,
proteins, starches, and dyes by the IHHI, plus further IHHI species, not
listed in Ved and Goraya’s (2008) market study, such as Sorghum bicolor, Theobroma cacao L., and Triticum aestivum L. (Sorghum is used in the production of malt extract [Indian Pharmacopoeia 2010] and T. cacao is used for cocoa butter). Similarly, several non-pharmacopoeia species of Pinus (P. kesiya Royle ex Gordon, P. nigra J.F. Arnold, and P. wallichiana
A.B. Jacks), absent from Ved and Goraya’s market list, occur in
potpourri. These species are likely used by the IHHI in general pine
oils that are used as aromatics (Leung and Foster 1996).
Although
the majority of UK potpourri items sourced from India relate to
medicinal or healthcare species, a significant number relate to species
used in wood production (Table 1). Occasionally these include plantation timber species such as mahogany, Swietenia macrophylla King, and hoop pine Araucaria cunninghamii Aiton ex D. Don, but more often are popular farm forestry species, e.g., Acacia auriculiformis, Alnus sp., Casuarina equisetifolia L., Combretum spp., Leucaena leucocephala, and Terminalia alata
Heyne ex Roxb. In general, potpourri items from such species involve
fruits and leaves, most likely byproducts from wood production.
According to Saigal et al. (2002),
when farm forestry was first introduced into India in the 1970s,
regulation of the felling of trees and transport of forest produce
inhibited its success, but during the 1980s, in various Indian states,
popular farm forestry species often became exempt from restrictive
transit and felling permit rules. Many ingredients in this post-1990
potpourri study seem to reflect this change in regulation.
Other potpourri items derive from remnant short lengths of materials from craft industries, including rattan cane stems (from Calamus acanthospathus Griff. and C. viminalis Willd.), “lata” stems (possibly from Finlaysonia obovata or other species), and shola pith from Aeschynomene aspera. Similarly, flowers from Schoenoplectus
may be byproducts from preparation of matting from their stems.
Surprisingly few Indian-sourced UK potpourri ingredients are also used
in the dried floristry trade, but examples listed in Table 1 involve a wide range of plant parts: inflorescences, flower heads, bracts, fruits, cones, leaves, leafy stems, and several fungi. Although Tillandsia usneoides (L.) L. is imported into India from Northern and Central America, some is likely re-exported.
Not all UK potpourri species sourced from India could be allocated to a single, specific economic sector (see Table 1, section D). For instance, for Cerbera odollam
Gaertn. there are several possibilities: medicine, biofuel, or
primary-use dried floristry. However, this cardioactive species is known
more for its toxicity and use in homicide and suicide (Gaillard et al. 2004) than for medicinal uses, and Lemmens (2006) concludes that there is little future for Cerbera
spp. in medicines (other than local uses) due to the availability of
similar, less toxic compounds in other species. However, Kansedo et al. (2009) describe C. odollom as a promising non-edible feedstock for biodiesel production.
North Africa and Middle East
From
North Africa and the Middle East, Israel was found to be the main
supplier (31 samples), followed by Morocco (4), Turkey (2), Iran (2),
and Egypt (1). Israeli samples were mainly from agricultural crops
including edible fruits (Citrus spp., Cucurbita pepo, Malus domestica Borkh., Prunus persica (L.) Batsch, Psidium guajava L., Solanum melongena L., and S. aethiopicum L.), nuts (Juglans regia L.), herbs (Laurus nobilis L.), cereals (Zea mays), and ornamentals (Dahlia, Hydrangea, Leucanthemum, Viola, and Zinnia). The Israeli bias reflects a specialist potpourri company that focused on items from Israel.
Europe
The
29 samples recorded from Europe were sourced from a wide range of
countries: UK (7), France (5), Norway and Italy (each 3), Czech Republic
(2), Russia, Poland, Portugal, Macedonia, and Hungary (each 1), and
unknown (4 samples).
Ingredients included algae (Chondrus from France), lichens (Cladonia from Norway), and cork oak bark (Quercus suber L. from Portugal and Italy). Flowers were sourced from Achillea and Consolida (UK), Chamaemelum (France), Erica, Malva, and Papaver (Eastern Europe), and leafy stems from Passiflora incarnata L. (from Italy). Cereal samples included Triticum aestivum and Phalaris canariensis L. (both from the UK), and timber-related ingredients included stems and stem slices of Betula (from Russia), Picea/Larix (from Czech Republic), Quercus and Salix/Populus from Italy, and Larix bark from UK. Cone and leaf samples from Pinus sylvestris L. from France or Eastern Europe also occurred.
Tropical Africa
In
all, 14 potpourri ingredients (21 samples) were sourced from tropical
Africa: 10 from South Africa, 2 from Zimbabwe, and 1 from West Africa;
the source of the remainder was unknown. Those from South Africa (Athanasia, Eucalyptus, Helichrysum, Leucadendron, and Protea species) reflect the dried flower industry. Other African ingredients included entire baobab fruits (Adansonia digitata L.) and fruits of Raphia hookeri G. Mann & H. Wendl.
Americas and Australia
Fifteen
ingredients (16 samples) originated from the Americas and Australia: 4
were from the US and Canada, 3 were Mexican, 7 Brazilian, and only 2
Australian (unsurprisingly Acacia and Eucalyptus). Brazilian ingredients included empty fruit cases of the Brazil nut (Bertholletia excelsa Bonpl.), entire fruits of Raphia taedigera (Mart.) Mart., fruit capsules of Jacaranda copaia (Aubl.) D. Don, an empty fruit of Parkia paraensis Ducke, Strychnos pseudo-quina A. St.-Hil. leaves, and inflorescences of Syngonanthus as well as the lichen Parmotrema. From North America were Nolina texana S. Watson leaves, Tillandsia usneoides (L.) L. aerial parts, and possibly stems of Salix.
Comparison of Potpourri Ingredients Marketed in UK and US
Tucker et al. (2010)
carried out a survey of potpourri ingredients used in the United States
and there are similarities to this study. Of the 215 species in the US
study, 121 occur in the UK potpourri ingredient list and 94 do not.
Conversely, over 200 ingredients in this UK study do not occur in the US
study. UK ingredients not listed in Tucker et al. (2010) include many food crop species, many Citrus
spp. and pulses, as well as other ingredients sourced from Eastern
Europe, North Africa and Middle East, Africa, and Thailand. US
ingredients not occurring in this UK study include many Australian and
South American imports as well as local North American ingredients.
However, many Indian species occur in both UK and US potpourri,
suggesting that Indian sources are a mainstay for potpourri, while
variations occur depending on geography and trade partners.
Conservation Issues: A Case Study Regarding Indian-Sourced UK Potpourri Ingredients
Overall
approximately 65% of Indian potpourri taxa relate to taxa used in the
IHHI as medicinal herbs or other ingredients (oils, dyes, gums, and
starches) for herbal formulations and products. These taxa include crops
(both Indian and imported) and NTFPs for which there is a long-standing
tradition of seasonal gathering within India. Traditionally, NTFP
collection was for subsistence or local needs, but nowadays sales to
industry provide a supplementary income for rural poor, often tribal
people. Saigal et al. (2002), Subrat et al. (2002), and Ved and Goraya (2008)
describe the Indian medicinal plant trade as an hierarchical network
that consists of tens of thousands of traders, from collection agents at
village level, to agents at road head markets or mandis, to stockists
or agents who operate from medium mandis, to well-organized commission
agents located in major cities such as Mumbai, Delhi, Chennai, and
Kolkata. Commission agents often have their own storage facilities and
tend to supply one or two major manufacturers in herbal healthcare.
Payments to collectors are generally low as they are often several
levels removed from the final buyer and may only get a fraction of the
final price, often as little as 3% according to Saigal et al. (2002). There have been calls to encourage more direct links between collectors and processors (Subrat et al. 2002), and initiatives regarding this were reported by Ved and Goraya (2008). Importantly, Kuipers (1997)
suggested that low prices obtained for seasonally gathered NTFPs may
encourage gatherers to “mine” resources rather than sustainably manage
them.
Table 1
shows that crops have the greatest representation within UK potpourri
sourced from India (68 taxa), but wild collected Indian native taxa are
significant too (48), and a further 35 can be both crops or wild
collected. Unfortunately, for the 67 taxa identified to species (not
just genus) that potentially contribute to wild collected potpourri
ingredients, IUCN global Red List assessments are not available for 53
(79%) of these, so significant knowledge gaps need to be filled. From
the 14 assessments available, 12 species were rated Lower Risk/least
concern, illustrating that some wild-harvested potpourri species are not
threatened; these include Aeschynomene aspera, Calophyllum inophyllum L., Caryota urens L., Cedrus deodara (Roxb. ex Lamb.) G. Don, Heritiera littoralis Aiton, Millettia pinnata (L.) Panigrahi, Picea smithiana (Wall.) Boiss., Pinus kesiya Royle ex Gordon, Pinus wallichiana, Punica granatum L., Shorea robusta Gaertn., and Sphaeranthus indicus L. (IUCN 2013).
Additionally several species within Schoenoplectus are also listed as Lower Risk/least concern (IUCN 2013). Many of these species occur in ruderal environments degraded by humans. Sphaeranthus indicus is a widespread weed in terrestrial freshwater habitats, with stable populations and only local threats. Aeschynomene aspera
is widespread and common in wetland margins and no specific threats are
noted. Similarly, other species, currently not assessed globally or in
India, are also widespread and common, e.g., Bombax ceiba L. (widely distributed in India), Dodonaea viscosa (L.) Jacq. (a pantropical weed), Ichnocarpus frutescens (L.) W.T. Aiton (throughout India to 1200 m), and Lycopodium spp. (wide ranging in Asia, Europe, and North America). However, the mangrove species Heritiera littoralis, although widespread and common globally, has a declining population trend, threatened by coastal development (Duke et al.2010). Other mangrove potpourri species include Helicteres isora L., Finlaysonia obovata, and Cerbera odollam,
and these may be similarly threatened by habitat change. Some local
evaluations reflect this, e.g., CAMP reports for Orissa described C. odollam as vulnerable (ENVIS–FRLHT 2012). Table 2
lists additional potpourri species of conservation concern within
Indian states. All are medicinal species traded at high volume except
for Cochlospermum religiosum (L.) Alston which is traded at lower volumes (Ved and Goraya 2008). For some there is a close link between potpourri parts and traded medicinal parts, especially as byproducts.
Table 2
Potpourri
species linked to medicinally traded species of conservation concern
within Indian states. (Data collated from CAMP workshop reports reviewed
by ENVIS–FRLHT [2012].)
Species
Conservation status within Indian states (with date of CAMP report)
Traded in medicine
Potpourri parts
Number of potpourri samples
Aegle marmelos
Vulnerable -
Maharashtra 2001, Karnataka 95/96/97/99, Tamil Nadu 95/96/97/98, Andhra Pradesh 2001
At the Indian national level, Oroxylum indicum (L.) Kurz is classed as “vulnerable” (Rao et al. 2003) but has not been assessed globally by IUCN (2013). This medicinal species is traded in high volumes in India (Ved and Goraya 2008),
primarily the roots but also seeds. The winged seeds were common in
Kew’s potpourri samples up to around 2004, but not subsequently. The
decline may reflect reduced medicinal trade owing to possible demise in
the wild. Global conservation assessments suggest that Pterocarpus marsupium
Roxb., whose natural distribution is restricted to India and Sri Lanka,
is probably of most concern. This is vulnerable v. 2.3 (IUCN 2013)
largely on account of its wood which is used as timber and for its
hypoglycemic properties, although the winged seeds are also traded
medicinally in India (Ved and Goraya 2008). Fruits in potpourri are likely byproducts from wood harvest or surplus medicinal fruits. More detailed study of Pterocarpus fruits in trade may be worthwhile; Rojo (1972) distinguishes various fruit characters and P. marsupium, P. indicus Willd., and P. macrocarpus Kurz are likely represented in Kew’s potpourri collection.
Dysoxylum gotadhora (Buch.-Ham.) Mabb. (synonym D. binectariferum Hook.f. ex Bedd.) is also of interest. This species has not been assessed globally. However, Ravikumar and Ved (2000) state that uses of D. gotadhora are similar to D. malabaricum Bedd. ex C. DC., which has wood used as a substitute for infected agar wood from the vulnerable v. 2.3, Aquilaria malaccensis Lam. (IUCN 2013). D. malabaricum is described as globally endangered by Ravikumar and Ved (2000), although it has not been assessed globally in the IUCN Red List (IUCN 2013), or by Rao et al. (2003) for India. Nevertheless, the fact that D. gotadhora samples occur in potpourri may indicate substitution of D. malabaricum. Further investigation on quality of medicinal products and conservation status of Dysoxylum species may be worthwhile.
Calamus andamanicus Kurz from the Andaman Islands is “vulnerable” in India (Rao et al. 2003) but is absent from Ved and Goraya’s (2008)
list of medicinally traded species. This species is valued in potpourri
and floristry as the attractive small fruits remain on the stem better
than other Calamus species. Harvest for floristry may be a contributory threat to this species, along with rattan uses (Fig. 4).
Fig. 4
Examples of potpourri ingredients from species of conservation concern particularly within India at national or state level: 1) Oroxylum indicum seeds EBC PP 551; 2) Calamus andamanicus infructescence EBC 634; 3) Dysoxylum gotadhora fruit and seed EBC PP 769; 4) Dysoxylum gotadhora fruit and seed EBC PP 777; 5) Cochlospermum religiosum fruit valves EBC PP 294; 6) Pterocarpus marsupium fruits EBC PP 740; 7) Boswellia serrata gum resin EBC PP 708; 8) Strychnos nux-vomica empty fruit EBC PP 150; 9) Aegle marmelos fruit rind EBC PP 70; 10) Aegle marmelos fruit with seeds and pulp EBC PP 695; 11) Schrebera swietenioides fruit capsules EBC PP 41.
There
is a need for further studies regarding the collection of wild, native
species from natural habitats within India to ensure over-collection
does not occur; the lack of conservation assessments for many species
needs to be addressed even though initial studies suggest that wild
collected species are more often common species, from ruderal or wetland
habitats, with widespread distributions.
Conclusions
From
1,000 potpourri samples examined over a 20-year period it was possible
to identify 546 different ingredients. These represent 492 angiosperms,
28 gymnosperms, 8 ferns, 5 lichens, 4 bryophytes, and 1 alga, and more
than 100 families. This large diversity of ingredients to some extent
supports the Tucker et al. (2010)
viewpoint that more or less anything botanically interesting can be
included in potpourri; however, botanical patterns in species
representation occurred. Over 50% of ingredients were from just nine
plant families and there was especially a preponderance of fruits from
Arecaceae, Fabaceae, Malvaceae, Pinaceae, Poaceae, and Rutaceae; leaves
from Arecaceae, Fabaceae, and Poaceae; inflorescences from Asteraceae;
seeds from Fabaceae, and stems from material and timber producing
species.
UK potpourri ingredients are
sourced from many parts of the world but the vast majority are sourced
from Asia, especially India. Thailand has recently become a base for
manufacture of UK potpourri and unique Thai ingredients have emerged,
but the majority of potpourri items are still byproducts from
ingredients used by the Indian herbal healthcare industry (e.g., Aegle marmelos, Areca catechu, Nelumbo nucifera Gaertn., Oroxylum indicum, Gossypium, Millettia pinnata, Pterocarpus, Soymida febrifuga (Roxb.) A. Juss., Thespesia populnea
(L.) Sol. ex Corrêa), while others are byproducts from species used in
other natural product-based industries notably timber (e.g., Araucaria cunninghamii, Swietenia macrophylla), pole wood (Acacia auriculiformis, Combretum spp., Terminalia alata), cane (Calamus spp.), and shola pith (Aeschynomene aspera).
In contrast to Asia, UK potpourri ingredients sourced from Africa, the
Middle East, Europe, America, and Australia are relatively few. The
identities of these ingredients suggest that many may be byproducts or
surpluses from crops of fruits, nuts, herbs, cereals, ornamental
flowers, and timbers.
There is a concern
that an expansion of the IHHI coupled with the hierarchical system of
trade in plants for this industry might result in over-collection in
wild harvested species. However, distinction between Indian crop and
wild harvested species is often blurred in the literature, and
geographical status of “wild” harvested species needs to be checked to
ensure they are not actually introduced, naturalized, or cultivated.
Furthermore, international conservation assessments (IUCN 2013)
are not available for almost 80% of wild collected Indian-sourced
potpourri species, albeit many are common species with widespread
distributions, often from ruderal or wetland habitats. Potpourri species
for which there is concern include Pterocarpus marsupium at an international level and Oroxylum indicum
at the Indian national level. Overall there is little evidence to
suggest that the potpourri trade itself exerts direct pressure on wild
species since its ingredients largely reflect direct use by other
industries (e.g., food, medicines, and materials), but there is
potential for potpourri packs to be a barometer of change in traded
species. Such studies could reveal use of substitutes (e.g., use of D. gotadhora rather than D. malabaricum or Aquilaria malaccensis), predict a downturn in previously abundant species (e.g., Oroxylum indicum), or show changes in habitat representation (e.g., decline in mangrove species such as Heritiera littoralis, Cerbera odollam, and Helicteres isora).
Acknowledgments
Sasha
Barrow, Laura Hastings, James Morley, Georgina Pearman, Helen
Sanderson, and Jill Turner worked on potpourri identifications and
reports. Identifications were provided by Susyn Andrews, Bill Baker,
Sally Bidgood, Nicola Biggs, Diane Bridson, Martin Cheek, Tom Cope,
Aaron Davis, Rogier de Kok, John Dransfield, Peter Edwards, Aljos
Farjon, David Goyder, Peter Green, Nicholas Hind, Gwilym Lewis, Eve
Lucas, Eimar Nic Lughadha, Terry Pennington, Alan Radcliffe-Smith, Lulu
Rico-Arce, Peter Roberts, David Simpson, Melanie Thomas, Bernard
Verdcourt, Kai Volleson, Dr Wadhwa, Paul Wilkin, Martin Xanthos, and
Daniella Zappi (Kew herbarium), Sandra Knapp and Jenny Bryant (Natural
History Museum), Arthur O. Tucker (Claude E. Philips herbarium), and
Peter Gasson and Paula Rudall (plant anatomy, Kew). Monique Simmonds
made invaluable suggestions regarding the text. Thanks are also extended
to the companies who commissioned Kew to review the identity,
sustainability, and safety of their products.
