- First Online:
- 20 November 2015
- Cite this article as:
- Cook, F.E.M., Leon, C.J. & Nesbitt, M. Econ Bot (2015) 69: 330. doi:10.1007/s12231-015-9325-8
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 WordsNon-timber forest products United Kingdom India Thailand plant families plant parts wild collected crops conservation status Indian herbal healthcare industry ethnobotany
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.
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. ), 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.
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.
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.
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).
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.
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.
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.
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:
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.
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)
Catunaregam spinosa (Thunb.) Tirveng. (syn. Gardenia latifolia Schltdl. ex Hook.f.) (papra)
Ficus benghalensis L. (banyan)
Ficus religiosa L. (peepul)
Juniperus sp. [and Indian imports *] (juniper)
Limonia acidissima L. (wood apple)
Millettia pinnata (L.) Panigrahi (syn. Derris indica (Lam.) Bennet, Pongamia glabra Vent., P. pinnata (L.) Pierre) (Indian beech, pongam oil tree)
Nelumbo nucifera Gaertn. (sacred lotus)
Pandanus sp.(screw pine, pandan)
Punica granatum L. (pomegranate)
Shorea robusta Gaertn. (sal)
Sida acuta Burm.f. (sweet berela)
Spondias pinnata (L.f.) Kurz (Indian hog plum)
Tamarindus indica L. (tamarind)
Terminalia alata Heyne ex Roxb. (Indian laurel)
Albizia lebbeck (L.) Benth. (Indian siris)
Aloe sp. likely A. vera (L.) Burm.f. (aloe vera)
Areca catechu L. (betel palm)
Carica papaya L. (pawpaw)
Carissa carandas L. (karanda)
Celosia argentea L. (cockscomb)
Cinnamomum sp. some likely C. verum J.Presl (cinnamon)
Cocos nucifera L. (coconut)
Coriandrum sativum L. (coriander)
Elettaria cardamomom (L.) Maton (cardamom)
Eucalyptus spp. (eucalyptus)
Gossypium sp. (cotton)
Illicium verum Hook.f. (star anise)
Luffa acutangula (L.) Roxb. (angled luffah)
Musa sp. (banana)
Pennisetum glaucum (L.) R.Br. (syn. P. typhoides (Burm.f.) Stapf & C.E.Hubb.) (pearl millet)
Senna alexandrina Mill. (syn. Cassia angustifolia M.Vahl) (senna)
Sesamum indicum L. (sesame)
Thespesia populnea (L.) Sol. ex Corrêa (portia tree)
Thymus spp. (thyme)
Zingiber officinale Roscoe (ginger)
3. Close relatives, confused species, substitutes, and alternatives for Indian herbal pharmacopoeia species
Millettia extensa (Benth.) Benth. ex Baker
Pterocarpus spp. (likely includes P. indicus Willd., P. macrocarpus Kurz) (bastard teak, gum kino)
Sterculia sp., possibly S. villosa Roxb. (udal)
Dactyloctenium aegyptium (L.) Willd. (Egyptian crowfoot grass)
Sapindus trifoliatus L. (soapnut)
Alcea rosea L. (syn. Althaea rosea (L.) Cav.) (hollyhock)
Luffa cylindrica (L.) M.Roem. (smooth luffah)
Pterocarpus soyauxii Taub. (West Africa)*
4. Additional Indian medicinal plant market species listed in Ved and Goraya 2008 (plus close relatives ǂ and other probable IHHI species †)
Bauhinia tomentosa L. (yellow bauhinia)
Combretum spp. (combretum)
Dodonaea sp. (hopbush)
Dysoxylum gotadhora (Buch.-Ham) Mabb. (syn. D. binectariferum Hook.f. ex Bedd.) ǂ
Ichnocarpus frutescens (L.) W.T.Aiton (unconfirmed identification)
Lagerstroemia sp. possibly L. parviflora Roxb. ǂ
Schrebera swietenioides Roxb. (weaver’s beam tree)
Soymida febrifuga (Roxb.) A.Juss. (Indian redwood)
Terminalia alata Heyne ex Roxb. (Indian laurel)
Wattakaka volubilis (L.f.) Stapf (syn. Dregea volubilis Benth. ex Hook.f.)
Cochlospermum religiosum (L.) Alston (silk cotton tree)
Corchorus sp. possibly Corchorus oliotorius L. (jute) ǂ
Dioscorea sp. probably Dioscorea alata L. (yam)
Flemingia strobilifera (L.) W.T.Aiton (wild hops) ǂ
Pinus kesiya Royle ex Gordon (khasi pine) †
Pinus wallichiana A.B. Jacks (Bhutan pine) †
Abelmoschus esculentus (L.) Moench (okra)
Ceiba pentandra (L.) Gaertn. (kapok)
Cucurbita pepo L. (squash, pumpkin) ǂ
Delonix regia (Hook.) Raf. (flame tree) ǂ
Helianthus annuus L. (sunflower)
Phoenix sylvestris (L.) Roxb. (date palm)
Pinus nigra J.F.Arnold (Austrian pine) †
Setaria italica (L.) P.Beauv. (foxtail millet)
Sorghum bicolor (L.) Moench (sorghum)†
Tagetes erecta L. (African marigold)
Theobroma cacao L. (cacao) †
Triticum aestivum L. (wheat) †
Zea mays L. (corn)
B. CRAFT MATERIALS AND WOOD SPECIES (Plantation timbers †; Farm forestry species ǂ)
Aeschynomene aspera L. (shola, sola)
Calamus acanthospathus Griff. (rattan)
Calamus viminalis Willd. (rattan)
Finlaysonia obovata Wall. (lata)
Schoenoplectus sp. (rush)
Combretum spp. (combretum) ǂ
Terminalia alata Heyne ex Roxb. (Indian laurel) ǂ
Acacia auriculiformis A.Cunn. ex Benth. (Australian wattle) ǂ
Alnus sp. (alder)* ǂ
Araucaria cunninghamii Aiton ex D.Don (hoop pine) †
Casuarina equisetifolia L. (Australian pine) ǂ
Leucaena leucocephala (Lam.) de Wit (leucaena) ǂ
Raphia sp. (raffia)
Raphia farinifera (Gaertn.) Hyl. (raffia palm)
Swietenia macrophylla King (big leaf mahogany) †
C. DRIED FLORISTRY SPECIES
Calamus andamanicus Kurz (rattan)
Daedalea quercina (L.) Pers. (oak maze gill fungus)
Lentinus polychrous Lév. (polypore fungus, white rot fungus)
Lenzites acuta Berk. (polypore fungus)
Microporus xanthopus (Fr.) Kuntze (yellow footed polypore)
Polystichum sp./p. (shield fern)
Pteridium aquilinum (L.) Kuhn (bracken fern)
Gomphrena globosa L. (globe amaranth)
Tithonia sp.(Mexican sunflower)
Picea smithiana (Wall.) Boiss. (West Himalayan spruce)
Anaphalis sp. (everlasting)
Bougainvillea sp. possibly B. spectabilis Willd. (bougainvillea)
Bracteantha bracteata (Vent.) Anderb. & Haegi (strawflower)
Casuarina equisetifolia L. (Australian pine)
Grevillea sp. (grevillea)
Gypsophila paniculata L. (baby’s breath)
Jacaranda mimosifolia D.Don (jacaranda)
Picea omorika (Pancic) Purk. (Serbian spruce)*
Samanea saman (Jacq.) Merr. (saman, rain tree)
Tillandsia usneoides (L.) L. (North America) (Spanish moss)*
Tsuga sieboldii Carrière/T. dumosa (D.Don) Eichler (Japanese hemlock)
D. SPECIES WHERE SOURCE ECONOMIC SECTOR IS UNCERTAIN
Calamus andamanicus Kurz (rattan)
Cardiopteris quinqueloba (Hassk.) Hassk.
Cerbera odollam Gaertn. (suicide tree)
Cheilanthes farinosa (Forssk.) Kaulf. (fern)
Combretum spp. (combretum)
Heritiera littoralis Aiton (looking glass mangrove)
Pterygota sp. (Buddha’s coconut)
Schima wallichii Choisy (needlewood)
Sparganium stoloniferum (Buch.-Ham.ex Graebn.) Buch.-Ham. ex Juz. (syn. S. erectum (Buch.-Ham.ex Graebn.) H.Hara ssp. stoloniferum (Buch.-Ham. ex Graebn.) H.Hara) (bur-reed)
Sterculia macrophylla Vent.
Annona squamosa L. (sugar apple)
Caryota urens L. (kitul, toddy palm)
Corchorus sp. possibly Corchorus oliotorius L. (jute)
Acacia binervia (Wendl.) J.F.Macbr. (Australia) (coast myall)*
Artocarpus altilis (Parkinson ex F.A. Zorn) Fosberg (breadfruit)
Helichrysum stoechas (L.) Moench (Europe) (shrubby everlasting)*
Hyphaene compressa H.Wendl. (E. Africa) (East African doum palm)*
Larix gmelinii (Rupr.) Kuzen. (E. Asia) (Dahurian larch)*
Magnolia sieboldii K.Koch (E.Asia) (Siebold’s magnolia)*
Pterocarpus rotundifolius (Sond.) Druce (Southern Africa) (round-leaved bloodwood)*
Spathodea campanulata P.Beauv. (West Africa) (African tulip tree)*
Trachycarpus fortunei (Hook.) H.Wendl. (windmill palm)
Zollingeria dongnaensis Pierre (Thailand)*
- 1)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;
- 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.
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.
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.
Potpourri species linked to medicinally traded species of conservation concern within Indian states. (Data collated from CAMP workshop reports reviewed by ENVIS–FRLHT .)
Conservation status within Indian states (with date of CAMP report)
Traded in medicine
Number of potpourri samples
Maharashtra 2001, Karnataka 95/96/97/99, Tamil Nadu 95/96/97/98, Andhra Pradesh 2001
Leaf, Fruit, Bark
Chhattisgarh 2003, Madhya Pradesh 2003/2006
Critically Endangered -
Madhya Pradesh 2003/2006, Chhattisgarh 2003
Karnataka 95/96/97/99, Orissa 2007, Rajasthan 2007
Fruits (halved capsules)
Near Threatened -
Andhra Pradesh 2001
Resin, Bark, Fruits
Madhya Pradesh 2003/2006, Andhra Pradesh 2001, Chhattisgarh 2003
Seeds, Stem or bark
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).
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.
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).
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.