Economic Botany through the Glass Flowers This lab is a self-guided tour. The families are ordered according to their order of display. Start anywhere and go from there Poaceae (mis-termed the Graminae) 9,000 species in 650 genera. Cosmopolitan distribution. Four (corn, wheat, rice, sugar cane) of the BIG 12. On display are a few edible grains including rice (Oryza sativa),tripsacum (Tripsacum dactyloides), and a species of grass from the same genus as barley (Hordeum vulgare). Notice the highly reduced flowers lacking petals and sepals but with elaborate, feathery stigmas perfect for catching wind-borne pollen in the flowers on display. Bromeliaceae: 2,000 species in 50 genera. Tropical and warm temperate America with a few African species. Pineapples (Ananas comosus) are native to the New World, and they quickly became an important in naval journeys for scurvy prevention. Arecaceae (mis-termed the Palmae) 2,780 species in 212 genera. Tropical. One (coconut) of the BIG 12. The brown, hairy coconut we think of is a seed, and the juicy bit is the endosperm. You can find the leaves on display. The coconut fruit is not on display. Araceae: Aroid family. 2,000 species in 110 genera. Largely tropical but with temperate memebers. Liliaceae 3,500 species in 250 genera. Cosmopolitan. Lily Family. Garlic, shallots, onions, leeks are all in the genus Allium. Musaceae 40 species in 2 genera. Wet lowland tropics of the Old World. One (banana) of the BIG 12. Orchidaceae 18,000 species in 750 genera. Cosmopolitan. Orchid Family. Piperaceae 2,000 species in 5 genera. Pantropical distribution. Pepper Family. This family contains black pepper (fruits of Piper nigrum) and Piper methysticum, from whose roots the popular South Pacific intoxicant kava kava is made. Neither of these plants are on display, but notice the specialized inflorescence called a spadix that is characteristic of this family. Fagaceae
Beeches, Oaks, and Sweet Chestnuts. 1,000 species in 8 genera. Frequently dominant in temperate forests and also found in some tropical forests. Many timber species (oaks, beeches, chestnuts) are found in this family, and the fruits of the genus Castanea are edible (chestnuts). The species in this family have separate male and female flowers, but both flower types are typically found on the same plant. Many have highly reduced flowers grouped into catkins, and wind-pollination is common in the group. On display here also is an example of a gallforming insect that parasitizes Castanea sativa (European chestnut). When laid in plant tissue, the eggs and larvae of the insect alter plant development, and the plant ends up making a special structure that houses the developing parasites. Compare the structure of the galls induced by the parasitic wasp to the structure of the plant fruit. Moraceae 3,000 species in 75 genera. Mostly tropical and subtropical with occasional temperate members. The fig family contains the edible figs (Ficus carica) and breadfruit (Artrocrapus altilis). This family tends to have complicated inflorescences folded in upon themselves. In the fig on display, look at the edible fruit made up of many tiny flowers. Notice how many different kinds of flowers are present. Species in the genus Ficus are pollinated by very small wasps, and the relationships between the fig and wasp species are highly specific and often complex. In all cases the wasp lays its eggs inside the flower, and a flower containing a wasp will not produce for the plant. In some species, the plant produces special sterile flowers just for wasp inhabitation. Check out the many different flower forms on display here. Another economically important family member is the mulberry species on which silkworms grow (Morus alba). Efforts to cultivate the silkworms on other mulberry plants have failed, often with spectacular consequences for silk trade. (You can read more in Bugs in the System by May Berenbaum.) Many species in this family produce latex, which can sometimes be a local source of rubber (e.g. Indian rubber, Ficus elastica). There is some argument over whether hemp (Cannabis sativa) and hops (Humulus lupulus) belong in this family or in their own family, Cannabaceae. Chenopodiaceae 1,500 species in 100 genera. Found in temperate and subtropical areas, often in saline habitats. One (sugar beet) of the BIG 12. On display is the species Beta vulgaris, from which we eat the leaves (chard) and the swollen hypocotyl (beets). The leaf crop and the hypocotyl crop are either from different varieties or from different seasons, with the storage organs best harvested in the autumn and the leaves best harvested in the spring. Other important members of this family are quinoa (Chenopodium quinoa) and spinach (Spinacia oleracea). Lauraceae 2,500 species in 32 genera. Found in the tropics and subtropics, with a few temperate species. Laurel Family This family contains a number of economically important species, but we use different members of the family for very different purposes. We use leaves (bay leaves), bark (cinnamon and camphor), and fruits (avacados). On display here are cinnamon (Cinnamomum zeylanicum), camphor (Cinnamomum camphora) and avocado plants (Persea americana). Incidentally, Haas avocados have the highest calorie per unit weight ratio of any fruit! Sassafras -- whose extract is now banned by the FDA in food products because of the carcinogenic effects of safrole, which is found in large quantities in the essential oil of sassafras -- was once the primary flavoring in root beer. The leaves of most species in this family contain many aromatic oils. Can you see the leaf oil cavities that are characteristic of this family?
Myristicaceae 380 species in 16 genera. Lowland forests of the tropics. Nutmeg Family Only one species, Myristica fragrans (nutmeg and mace), in this family is widely used. Nonetheless, this family is considered economically important because of its enormous historical impact on exploration, trade, and politics in the 17 th 19 th centuries. In all members of this family, male and female flowers are found on different plants, and the flowers have no petals, only sepals. Notice how there's a single carpel (or at least what looks like a single carpel) with a single seed in each female flower. Nutmeg comes from the seeds of M. fragrans, while mace is derived from the bright red aril surrounding the seed. The aril is an elaboration and outgrowth of the ovule stalk. A rich history of nutmeg and the early spice trade can be found in Nathaniel's Nutmeg by Giles Milton. Brassicaceae (mis-termed the Cruciferae) Mustard Family 3,000 species in 380 genera. Cosmopolitan. This family includes a number of important edible plants including yellow (Brassica alba) and black mustard (Brassica nigra),bok choi (Brassica chinensis), turnip (Brassica campestris), canola (Brassica napus), horseradish (Armoracia rusticana), wasabi (Wasabia japonica), and the species Brassica oleracea from which cabbage, brussel sprouts, broccoli, cauliflower, and kohlrabi are derived. Raphanus sativus (radish) is on display here. The members of this species contain distinctive compounds called glucosinalates or mustard oils. The flowers of this family are all very similar: four sepals; four petals in a cross pattern (hence Cruciferae ); six stamens; two carpels. See if you can see all these parts in the flowers on display. Saxifragaceae 1,250 species in 80 genera. Cosmopolitan. Currants and gooseberries (members of the genus Ribes, especially Ribes nirgum or blackcurrant) are members of this family. Rosaceae 3,370 species in 122 genera. Cosmopolitan. Many of our edible fruits come from this family. Edible fruits include: apples (Malus domestica), raspberries and blackberries (Rubus sp.), plums (Prunus americana), apricots (Prunus armeniaca), peaches (Prunus persica), almonds (Prunus dulcis), quince (Cydonia oblanga), strawberry (Fragaria ananassa), pears (Pyrus communis) and cherries (Prunus avium, sweet cherries, and Prunus cerasus, sour cherries). Many of these are anciently cultivated. Many thousands of apple varieties exist today, but even in Roman times over 20 varieties were widely recognized and used. This family exhibits remarkably variable flower structure. There are typically five showy petals and many free stamens. There may be many free carpels (e.g. strawberries and raspberries), a few fused or semi-fused carpels (e.g. apples), or a single carpel (e.g. cherries, plums, peaches). Often there is a floral cup or receptacle, but again the floral structure can range from a superior ovary to an ovary completely surrounded by the floral cup. Look at the specimens on display and compare the flowers and fruits. Look familiar? Tasty? What kind of floral structure is responsible for each of the edible fruits listed above? Fabaceae (mis-termed the Leguminosae) 17,000 species in 700 genera. Cosmopolitan. Two (common bean and soybean) of the BIG 12. This is the legume family, a huge family of dicotyledonous plants. Many species are intimately associated with nitrogen-fixing bacteria, and thus the seeds of these species are often rich sources of protein. Not a single economically important bean is on display, however. By far the most important
beans are the soybean (Glycine max) and common bean (Phaseolus vulgaris), from which black beans, pinto beans, navy beans, kidney beans, etc. are derived. Other important members of the family are lentils (Lens culinaris), peanuts (Arachis hypogaea), carob (Ceratonia siliqua), peas (Pisum sativum), and tamarind (Tamarindus indica). The family contains three large groups that are easily distinguished by their flower structure. Mimosoid legumes have five regular. symmetrical petals and lots of stamens. Caesalpinoid legumes have slight to exagerrated symmetry in their flowers, but still they have five showy petals and ten or fewer stamens. Papilionoid legumes have a typical pea flower with a keel, two wing, and a standard petal. Other species in this family are used for timber and exudates (e.g. gum arabic and guar gum). Erythroxylaceae 260 species in 4 genera. Tropical and subtropical. Cocaine (Erythroxylum coca). Linaceae 300 species in 13 genera. Largely temperate with a few tropical species. Here it is flax (Linum usitatissimum)! In order to make linen out of flax, you must harvest the stems, leave them to decompose partially due to the action of bacteria (retting), and then process the remaining phloem fibers to form thread or cord. Flax was of large economic importance before the invention of the cotton gin and mechanical processing of cotton. Flax has recently come into the public eye again for its seed oil, which is promoted as a rich source of omega-3 fatty acids. It is perhaps worth noting that this highly unsaturated oil is also called linseed oil and used as a furniture polish. Rutaceae 900 species in 150 genera. Tropical and warm temperate regions. The citrus family. We consume the fruits of many trees in this family, and crops include limes, oranges, lemons, pommelos, tangerines and grapefruits. Many of the cultivated species are artificially generated hybrids, including the sweet orange (Citrus sinensis) on display. The juicy part of the fruit is made up of many succulent hairs derived from innermost layer of fruit tissue (endocarp). Burseraceae 500 species in 17 genera. Tropical. Contains the species from which frankincense (Boswellia sacra) and myrrh (Commiphora abyssinica) are derived. Both of these scents are derived from resins. Meliaceae 550 species in 50 genera. Tropical and subtropical. Mahogany family. Euphorbiaceae 5,000 species in 300 genera. Largely tropical with some temperate species. One (cassava) of the BIG 12. Lots of poisonous plants, plus a few like cassava that are only slightly poisonous. Anacardiaceae 600 species in 77 genera. Mangos, cashews, tung, pistachios and pink pepper (on display).
Aquifoliaceae 400 species in 3 genera. Temperate and tropical. Holly family. Malvaceae 1,000 species in 80 genera. Cosmopolitan distribution with high diversity in South America. The most economically important plant in this family is cotton (usually Gossypium hirsutum, but other members of the genus are used locally). Okra (Hibiscus esculentum) is also a member, as are the ornamental hibiscus plants. The flowers of this family are lovely and unusual. The male parts have fused together to form a tube around the gynocium, and the style is branched. Sterculiaceae 700 species in 60 genera. Pantropical. We tend to associate this family with the pleasant scents of its two most economically important plants, chocolate (Theobroma cacao) and Cola (Cola acuminata). Nonetheless, the family is named for Sterculius, the Roman god of toilets, because many members of the family have foul-smelling leaves and flowers. (Stercus is Latin for dung.) The original flavoring for cola drinks came from the seeds of the cola plant, but now most soda flavoring is synthetic (cf. Sassafras in the Lauraceae). Cocoa, cocoa butter and chocolate are all derived from the seeds of the cocoa plant. All of these products require a good deal of processing. The original, local harvest of the fruits often focused on the yellowy fruit tissue surround the seeds, which is sweet but mild or bland in flavor and quick to decay. Notice how the flowers and fruits of cocoa are borne directly on the trunk! This is not so uncommon in the tropics, but it is fairly unusual in the temperate flora. Caricaceae 30 species in 4 genera. Found in tropical South America and Africa. The papaya (Carica papaya) is the only economically important species of this family. Papaya is notable for its strange growth form: the tree is spindly with leaves only toward the crown, and it looks entirely too delicate to hold up the enormous fruits. If you happen to go to Cuba, call this popular, everpresent fruit "fruta bomba." Papaya is a vulgar slang word for female genitalila. Punicaceae 2 species in 1 genus. Southern Europe to the Himalayas. Pomegranate. Myrtaceae 3,000 species in 100 genera. Tropical and subtropical. Cloves (Syzgium aromaticum) and allspice (Pimenta dioica) are from this family. Apiaceae (mis-termed the Umbelliferae) 3,000 species in 300 genera. Cosmopolitan, often in uplands. Carrots, parsnips, and lots of spices are in this family. Ericaceae 3,000 species in 100 genera. Cosmopolitan. Heath family. This family is locally important because it is tolerant of acidic, sandy soils such as those commonly found in New England. Blueberries (Vaccinium sp., some on display), cranberries
(Vaccinium macrocarpon, on display), and wintergreen (Gaultheria sp., on display) are all in this family as are rhododendrons and azaleas (Rhodorendron sp., on display). The edible fruits. Don t, however, randomly munch on members of this family because many are quite toxic. Sheep laurel (Kalmia angustifolia, on display) is so called because sheep eat it and poison themselves. Emerson waxes poetic about the native rhodora (Rhododendron canadense, on display). You can compare the specimen on display to the poem below and decide whether it deserves the hype or whether Emerson was just under the influence of the long New England winter. The Rhodora On being asked, Whence is the flower? In May, when sea-winds pierced our solitudes, I found the fresh Rhodora in the woods, Spreading its leafless blooms in a damp nook, To please the desert and the sluggish brook. The purple petals, fallen in the pool, Made the black water with their beauty gay; Here might the red-bird come his plumes to cool, And court the flower that cheapens his array. Rhodora! if the sages ask thee why This charm is wasted on the earth and sky, Tell them, dear, that if eyes were made for seeing, Then Beauty is its own excuse for being : Why thou wert there, O rival of the rose! I never thought to ask, I never knew: But, in my simple ignorance, suppose The self-same Power that brought me there brought you. Sapotaceae 800 species in 50 genera. Pantropical. Some local uses of the fruits (e.g. the star apple, Chrysolphyllum cainito) and gums. Chicle, the original component of chewing gum, derives from Manilkara zapota. Ebenaceae 500 species in 2 genera. Tropical with a few temperate species. Ebony family. Oleaceae 600 species in 29 genera. Cosmopolitan. Olive family. Olive, ash, jasmine, lilacs. Apocynaceae 1,500 species in 180 genera. Pantropical. Convulvulaceae 1,800 species in 50 genera. Cosmopolitan. One (sweet potato) of the BIG 12. Sweet potatoes (Ipomea batata) comes from this family, as do morning glories (Ipomea sp.) Lamiaceae (mis-termed the Labiatae) 3,000 species in 200 genera. Cosmopolitan.
This is the mint family, characterized by the flowers with lipped petals. Many of our most commonly used herbs (e.g. mint, basil, oregano) are members of this family. No economically important species on display, although the genus Monarda contains wild bergamot (Monarda didyma). This is not to be confused with the bergamot found, for instance, in Earl Grey tea true bergamot is in the citrus family (Rutaceae). Solanaceae 300 species in 90 genera. Cosmopolitan. One (potato) of the BIG 12. Potatoes, eggplant, tobacco, chili peppers, tomatoes. Rubiaceae Coffea arabica. Cucurbitaceae Cucumbers, gourds, melons. Luffa sponges are made from the fibers in the fruits of certain species. Check out the highly convoluted stamens characteristic of his family. Yuck! Asteraceae 25,000 species in 1,100 genera. A large family with few economically important members. Lettuce, safflower, tarragon, chicory, and artichokes come from this family. Very distinctive inflorescence structure. Information about species numbers and distributions from: Heywood, V.H. (ed.) 1993. Flowering Plants of the World. Oxford University Press; Oxford. Written by Amity Wilczek, 2003