What’s the difference between a plant’s “seed” and its “fruit”? As I was writing the draft of this blog post, it dawned on me that I should have published it BEFORE the Coconut Palm (Cocos nucifera) post so that my two readers would have an answer to this question before tackling the problem of what it is that hit you when you’re “bonked” on the head by a ripe coconut. Oh, well: better late than never.
This single blog posting can’t cover all of the topics related to fruits and seeds: just listing and defining all of the terminology and jargon would require several editions! What I will do here is cover a few basic concepts and include some images to illustrate them. I also included links to several good online sources where you’ll find more detailed information on specific aspects of the botany of seeds and fruits.
What is a Seed and How is it Produced?
Flowering plants have specialized male and female reproductive organs. The male organ (stamen) contains an anther, which produces pollen. The female organ (pistil) contains an ovary, which contains ovules. The pollen is transported from the stamen into the pistil (by insects and other animal pollinators, or by mechanical means such as wind and water). When a pollen cell successfully fertilizes an egg cell within an ovule, a seed is produced from the ovule.
Basically, a seed is an embryonic plant enclosed in a covering (the seed coat or testa) along with some nutrient stores. It is composed of few basic parts: the seed coat, embryonic leaves, some form of nutrient stores, an embryonic root (or radicle, the first structure to emerge from the seed at germination quickly penetrating deep into the soil, forming a single unbranched taproot), and the plant embryo itself. The seed coat protects the internal parts of the seed prior to germination. The seed germinates when the embryo is exposed to water, swelling the embryo and bursting the seed coat. During this early phase of growth, the embryo has no means of photosynthesis, so the nutrient stores serve as a high-energy food source.
The Seeds of Monocots and Dicots
A seed needs a supply of food to support the embryonic plant until it is mature enough to process soil nutrients on its own. Monocots and Dicots (the two major groups of modern plants) accomplish this task in two very different ways. The cotyledon is the first leaf or leaves forming the seed and containing the food supply for the new seedling. Endosperm is the food contained inside the seed coat that feeds the embryo when it first germinates.
Parts of a Monocot seed.
A monocot seed has only one seed leaf (“monocot” is short for “monocotyledon”). In a monocot seed, there is usually a supply of food, called endosperm, inside the seed coat but separate from the cotyledon. The seed pods or fruits of monocots usually have a simple construction and are often large and fleshy. When a monocot seed germinates, it produces only a single leaf.
The parts of a Dicot seed.
A dicot seed has two cotyledons (“dicot” is short for “dicotyledon”).In dicot seeds, the cotyledons contain the endosperm. Note that there are some exceptions to this, and that some seeds of monocots do not contain endosperm. The fruits and the seeds vary considerably in shape, size, and texture. The seedpod can have any number of chambers, from none to many. There are often more seeds in a dicot fruit than in that of a monocot. When a dicot germinates, it produces two seed leaves. They contain the food for the new plant, so they are usually thicker than the true leaves. The first true leaves are often a different shape than that of the seed leaves.
Seed Size
The size of a plant’s seed is an important factor in its ability to adapt to and thrive in its environment. Plants that have smaller, more compact seeds expend less energy and nutritional resources, and so produce many more seeds per individual plant than do plants with larger seeds. Small seeds mature quickly and so are dispersed sooner; this is an advantage in a harsh environment with a short growing season. Annual plants generate large quantities of small seeds, ensuring that at least a few will survive and germinate successfully. Conversely, herbaceous perennials and woody plants generally have larger seeds and are able to produce them over a longer period of time. An additional advantage is that larger seeds contain more energy reserves to devote to germination and seedling growth, and so they produce larger well-established seedlings that are more likely to survive.
Fruit: a Definition
A fruit is a ripened ovary, the means by which a flowering plant disseminates and propagates its seeds. As the developing seeds mature, the ovary that contains them begins to ripen. The ovary wall (pericarp) may become fleshy, forming berries or drupes, or it may form a hard outer covering, as it does with nuts.
Types of Fruit
Simple Fruit – This type of fruit is a single ripened ovary that is produced from a single flower.
- Fleshy Fruits: A type of simple fruit where all or most of the ovary wall (pericarp) is soft or fleshy at maturity.
- Berry: A fleshy fruit where the entire pericarp is fleshy, although the skin of the fruit is sometimes tough. This fruit may contain only one seed or many seeds. Papaya, guava, and avocado are considered to be berries. The banana’s fruit is a seedless “false berry” technically known as an “epigynous accessory fruit” that develops without the benefit of pollination and fertilization (known as a “parthenocarpic berry”).
- Drupe: This is a type of fleshy fruit with a hard inner layer (the endocarp or “stone”) that encloses the seed. An example is the Kukui nut, which has a fleshy green outer husk enclosing a seed-bearing stone. The Kukui fruit is also referred to as a “drupaceous nut”. The Coconut Palm’s fruit is a dry “fibrous drupe” with a green, waterproof outer layer (exocarp), a thick fibrous husk (mesocarp), and a hard, woody inner layer (endocarp) that encloses a large seed. The actual seed embryo is embedded in the coconut “meat” (endosperm). The nutrient-rich “coconut milk” is liquid endosperm that has not yet formed solid tissue with well-defined cell walls. (See the blog post “The Coconut Palm“.
- Dry Fruits: Pericarp dry at maturity.
Legume: A type of Simple Dry Fruit that consists of an elongate seed-containing “pod” that opens by splitting (dehisces) along two seams. It is the typical fruit of the legume family (Fabaceae). The pod (referred to as a “dehiscent dry fruit”) is actually a single modified leaf (or carpel) that is folded over upon itself and fused along its edges.
Capsule: A dry fruit that releases its seeds when ripe; it is formed from several fused carpels and contains many seeds. Capsule splits open in various ways, usually along several definite seams. Capsules typically split open into well-defined sections or carpels which represent modified leaves. Examples: Jacaranda, Agave, and Castor Bean.
Compound (or “Aggregate”) Fruit – The fruit develops from a single flower with multiple pistils. Strawberry and raspberry fruits are examples of this type of fruit.
Multiple Fruit – A type of Compound Fruit wherein several flowers, each with a single ovary, produce small individual fruits that are fused together, forming a larger fruit (called a “syncarp”), as in that of the Pineapple, Bread Fruit, and Hala (Pandanus). This type of fruit consists of numerous flowers arranged along a pair of interlocking helical axes. Each flower develops into a fleshy fruit that is pressed against those of adjacent flowers, forming a mass of fruits that appears to be a single fruit.
Examples of Fruits of Common Hawaiian Plants
Fruit of the Autograph Tree.
Clusia rosea (= Clusia major) – Autograph Tree, Strangler Fig. The poisonous (and decidedly outlandish-looking) fruit is a green dehiscent (opens at maturity) capsule 5-8 cm in diameter. When ripe, it splits open from the top along several seams, revealing many bright-red seeds surrounded by a sticky, resinous flesh that enables the broadcast seeds to adhere to almost any surface they come into contact with. The seeds are edible and very attractive to birds, insects (particularly ants), and other wildlife. They germinate readily and easily in almost any soil, and so the Clusia rosea has become naturalized in Hawaii, particularly on Maui.
Fruit of the Balloon Plant.
Asclepias physocarpa – Balloon Plant – Native to southeast Africa; it is an invasive weed in Hawaii, but it has become naturalized. The fruit is a pale-green capsule about three inches in diameter. It is shaped like an inflated sphere (called a “follicle”) and is covered with numerous green pliable spines. The follicle splits at maturity, releasing numerous white thistles that are easily broadcast on the wind.
Maturing fruit of the Ironwood Tree.
Casuarina equisetifolia – Ironwood Tree – The fruit is a small woody structure (about 2.5 cm long and 1.5 cm in diameter) that resembles the “cone” of a coniferous tree. It consists of many carpels (or bracteoles) that each contain a single seed (a true nut) with a small membranous wing (samara). When the fruit is mature, the fruit disintegrates, releasing the nuts to be broadcast by the wind or by other mechanical means. The cone-like fruit is abundant, especially on healthy mature trees, and forms only on the heads of the pistillate flowers (http://www.botany.hawaii.edu/faculty/carr/images/cas_equ_mf.jpg). Immature fruit is green and covered with fine whitish-green bristles. When ripe, it becomes a hard, brown, warty-looking ball of spikes 1-2 cm in diameter, longer than it is wide, with a somewhat cylindrical shape. Each fruit contains a single winged nutlet about 6 mm long; these are cast upon the wind when the ripened cone splits in two.
Fruit of the Candlenut Tree.
Aleurites moluccana – Candlenut, Kukui – The green to brownish fruit is an ovoid indehiscent drupe 5 to 7 cm in diameter. the seed (2.5 to 3.5 cm in diameter) inside has a very hard seed coat (a hard and woody shell, superficially resembling that of a walnut) and a high oil content. The seeds may take as long as four months to germinate. The Candlenut is the official tree of the State of Hawaii and the island of Moloka’i. Ancient Hawaiians used its oil for light, fuel, medicine, soap, and fabric dye. The dried seeds are still used in lei making. The shells, which can be polished to a high luster, are fashioned into earrings and other costume jewelry. Oil extracted from the seeds was traditionally used by Hawaiians as a preservative for surfboards. The oil was also burned in lamps for illumination. When properly refined, the oil can be burned as fuel in diesel engines. During the 19th century, Kukui nut oil was a profitable commercial export of Hawaii. Currently, the primary commercial product derived from the fruit is the polyunsaturated oil extracted from the seed for the cosmetics industry. The oil contains linolenic and oleic acids. The refined product is famous for its ability to easily penetrate and soothe dry or sunburned skin, and for its effectiveness in treating other skin conditions such as psoriasis, acne, and eczema.
Banana tree with maturing fruit and male portion of fruiting body.
Musa sp. (Musa paradisiaca) – Banana, Mai’a – The fruit of the domesticated banana is a seedless parthenocarpic berry: that is, it develops without the benefit of pollination and fertilization, thus producing no seeds. The complex inflorescence (flower) is a terminal spike that originates as a transformed growing point on the plant. It emerges as a single large ovoid dark-purple bud. The bud then opens, revealing several rows of dozens of bright-white male, neuter, and female flowers. Male flowers occupy the uppermost rows and female flowers occupy the 5 to 15 lowermost rows. Approximately one day after the flower clusters, the male flowers are shed, leaving the upper stalk of the bud stem naked, except for the very tip where an unopened bud contains the last-formed of the male flowers. It takes about one year for a plant to develop mature fruit. The slow-growing fruits develop from the female flowers, forming clusters of slender green fingers that eventually become a “hand” of as many as 20 tiers (as much as 20 fruits to a tier) of maturing fruits. Each plant may produce as many as nine hands of fruit. The fruit-producing stalk soon bends under its own weight, causing the hands to grow upside-down. The total of the hanging clusters is known as a “bunch” or “banana stem”, and can weigh 30 to 50 kg. The individual “fingers” turn from deep green to yellow when mature. Each finger has a protective outer layer (“skin” or “peel”) and range in size from 10 to 30 cm in length. The flesh is ivory-white to yellow or salmon-yellow, may be firm, astringent, even gummy with latex when unripe, eventually turning tender and slippery when ripe. Wild banana varieties do produce by means of pollination and so may be nearly filled with numerous tiny black, hard seeds and have scant flesh. The common cultivated varieties are generally seedless with just the vestiges of minute ovules visible as brown specks in the slightly hollow or pithy center of the fruit, especially when the fruit is over-ripe.
Fruit of the Breadfruit Tree.
Artocarpus altilis – Breadfruit, Ulu – The Breadfruit is a monoecious tree, producing large numbers of tiny male and female flowers on the same plant. The male flowers emerge first, followed by the female flowers are massed together (1,500 to 2,000 flowers) in a large (more than 6 cm long and 4 cm across) roughly spherical prickly green flower head (capitulum) that develops into the distinctive compound fruit (or syncarp). The grapefruit-sized ovoid fruit (10-30 cm in diameter) has a rough surface. The outlines of the original female flowers are visible on the surface of the fruit as hexagonal polygons (known as achenes). Each achene is actually a single fruits that contains a seed. As the fruit matures, the rind is green at first, turning yellowish-green, then yellow or yellow-brown when ripe. During the green stage of the fruit’s development, the fruit is hard and the interior is white, starchy, and fibrous. When fully ripe, the fruit is soft, the interior is cream colored or yellow and pasty, and has a sweet fragrance. The fruit is borne singly or in clusters of two or three at branch tips. Hundreds of both seedless and seed-bearing breadfruit cultivars have been identified throughout the world. The seed-bearing varieties are grown from seeds that must be planted when fairly fresh because they lose their viability after only a few weeks. The seeds are roughly ovoid, rounded at one end and pointed at the other, and are about 2 cm long. The seedless cultivars are grown from suckers that naturally spring up along the roots of mature trees. Some of the seedless varieties still bear tiny (3 mm) abortive seeds in the core of the fruit. Breadfruit is one of the most productive food plants in the world. Depending upon rainfall amounts, an individual tree typically may produce more than 200 fruits annually.
Fruit of the Jack Bean.
Canavalia cathartica – Jack Bean, Maunaloa, ‘awikiwiki – A perennial climbing herb naturalized in Hawaii. Introduced goats and pigs have wreaked havoc on Canavalia on the Hawaiian Islands and made some nearly extinct; it may be that these lost their chemical defenses as no herbivorous mammals existed in their range until introduced by humans. It produces larger and heavier fruit (pods) and seeds than the other members of the genus Canavalia sp. The very substantial pods (8-14 cm long, 3-5 cm wide) contain as many as six reddish-brown to dark-brown seeds (about 2 cm long). The very active and abundant vines routinely climb anything from trees to telephone poles with great speed. The Hawaiian name (‘_wikiwiki) means “the very quick one” and comes from the word for “fast”.
Maturing Castorbean fruit.
Ricinus communis – Castor Bean – The fruit of the Castor Bean plant is a greenish- to reddish-purple, spiny globe-shaped capsule (2-3 cm in diameter) suspended on an elongated stem (pedicel). It turns brown when ripe. Each fruit contains three relatively large (0.5-1.5 cm) mottled brown ovoid seeds. Interestingly, the seeds possess a warty appendage referred to as a caruncle, a type of elaiosome. This structure is rich in lipids and proteins. Its purpose is to attract ants, who then carry the seed to their colony and feed the elaiosome to their larvae. After the larvae have consumed the elaiosome, the ants take the seed to the colony’s waste-disposal area, which is rich in nutrients from the ant frass and dead bodies, where the seeds germinate. This type of seed dispersal is termed myrmecochory from the Greek “ant” (myrmex) and “dispersal” (kore). The seeds (as well as the rest of the plant) contain the deadly toxin ricin. Four to eight seeds is considered a lethal dose for adult humans. However, incidents of actual poisoning are rare. Poisoning usually occurs when animals ingest broken seeds or break the seed coat by chewing. Intact seeds may pass through an animal’s digestive tract without releasing the toxin. The toxin protects the plant from damage by insect pests and is also the source for undecylenic acid, a natural fungicide. Castor Bean seed is the source of castor oil, which has a wide variety of industrial and pharmaceutical uses, and is rich in triglycerides, mainly ricinolein, the active ingredient that enables the use of castor oil as a purgative and as a solvent for several medically useful alkaloids.
Fruit, foliage, and flowers of Crotalaria retusa.
Crotalaria retusa – Rattlepod – An invasive annual herb with attractive yellow flowers and large (3-5 cm long) iridescent dark-brown to black fruit (pods). In Hawaii, this species has escaped from cultivation and become naturalized in disturbed sites such as roadsides, dump sites, and urban areas. The fruit contains about 23 small (about 4.5 mm) tan-colored seeds per pod. The seeds contain alkaloid compounds that are moderately to very toxic to birds and mammals.
An individual corm (fruiting body) of Elephant Grass.
Pennisetum purpureum – Elephant Grass, Merker Grass, Napier Grass – A tall (2-3.5 m, rarely up to 7 m), robust perennial grass that has become naturalized in Hawaii, but is considered to be a noxious weed. Seeds are propagated by wind, water, animals, and burnoffs. Also propagates by vegetative growth. The inflorescence is a panicle (a loose, multi-branched cluster of flowers) holding numerous small (about 2 mm long) fruiting bodies known as caryopses. A caryopsis is a type of simple dry fruit: one that is formed from a single carpel, does not open at maturity (indehiscent), and resembles an achene, except that in a caryopsis the fruit wall (pericarp) is fused with the thin seed coat, forming a single unit. The caryopsis is popularly referred to as a grain and is the fruit typically produced by members of the grass family (Poaceae or Gramineae), such as wheat, rice, and corn. Although it has a very high productivity of overall plant material and an extensive and vigorous root system that allows it to forage widely for moisture and nitrogen, it has relatively low seed production and its natural rate of propagation is fairly slow.
Common Guava blossom, fruit, and leaves.
Psidium guajava – Guava, kuawa, kuawa ke‘oke‘o, kuawa lemi, kuawa momona – The fruit is a true berry, roughly ovoid or pear-shaped, 10-15 cm long, and weighing as much as 500 grams. Its skin is yellow when ripe. The pulp is very juicy and colored creamy-white or creamy-yellow to pink or red. The soft pulpy core (endocarp) contains many cream to brown kidney-shaped or flattened seeds. Birds, frugivorous bats, livestock, and feral animals consume the fallen fruit and spread the seed. Edible fruit and hard seeds allow the guava to spread throughout pastures and natural areas forming dense stands of trees that shade out the understory plant species. Guava is one of the most noxious weeds of pastures because it is able to infest large areas quickly.
A grasshopper eating the spent flower of a Hairy Abutilon.
Abutilon grandifolium – Hairy Abutilon, Hairy Indian Mallow – A large (2 m high) shrub with broad (4-6 cm wide) leaves. The fruits are schizocarps (a dry, dehiscent fruit that develops from multiple carpels splits into multi-seeded mericarps when mature) about 1.5 cm in diameter and 1 cm tall. Abutilon’s mericarps usually contain six or more seeds, are think-walled, and somewhat inflated. The seeds are blackish, reniform, and 2-3 mm long. In Hawaii, the Hairy Abutilon is naturalized in waste areas, fields, and along roadsides, especially in arid regions.
Hala Tree (Pandanus tectorius) fruit.
Pandanus tectorius – Screwpine, Hala – The fruit (a multiple fruit or syncarp) is usually ovoid, ellipsoid, or globe-shaped with a maximum diameter of 20-30 cm. It strongly resembles the fruit of the Pineapple. The fruit is comprised of 38-200 wedge-like phalanges (known as “keys”) that have an outer fibrous husk. Individual keys contain 2-8 seeds. They are buoyant and the seeds within them remain viable for several months while being transported by ocean currents.
Immature berries of the Tree Heliotrope.
Heliotropium foertherianum – Tree Heliotrope – (formerly Tournefortia argentea and Argusia argentea) – Naturalized in Hawaii, where it was introduced in modern times. Tolerates shallow, highly saline, and infertile coastal soils and pure sand; it has been known to take root on bare rock. It can grow very close to the waterline where occasional waves wash over its root system and the lower trunk. The numerous pea-sized (5-8 mm in diameter) fruits are smooth and globular, their color ranging from bright white to greenish white to light brown when mature. Each fruit eventually divides into two to four pale nutlets and carries two to four seeds in pale-colored corky tissue. The Tree Heliotrope propagates by both seed and vegetative growth. The seeds float and are dispersed by ocean water, germinating readily after spending weeks in the water.
Seed pods of the Hop Bush.
Dodonaea viscosa – Hop Bush, ‘a ‘ali’i, Kumakani – This species is notorious for its tendency to display a lot of variation in its size and physical appearance within its natural geographic range. The small (1.5-2 cm long) flowers grow in branching clusters. Individual plants may have only male flowers, only female flowers, or both on the same plant. Only the female flowers develop into the characteristic fruit, a two- or four-winged capsule (1.5 cm long) containing two to four round black seeds (0.5 cm in diameter). The color of the capsules range from straw-colored to brown, pink, dark red, to reddish purple. Streaks of color and mottling are common.
Fruit and leaves of the Pilo or Hupilo.
Coprosma montana – Alpine Mirror Plant, Pilo, Hupilo – Native to Maui and the Big Island, this species is common at high altitudes (6000 – 10,000 ft). The greenish inconspicuous flower produces fruit in the form of a round drupe about 6 mm in diameter with small but distinctive “calyx teeth” at the apex. The shiny attractive fruit ranges from yellow to bright orange or red, to dark orange, turning black at maturity. Each fruit contains two half-round nutlets and has an unpleasant taste (but is not poisonous).
Mature seedpods of the Jacaranda Tree.
Jacaranda (Jacaranda mimosifolia) – Flat, ear-shaped woody seed pods appear on the branches toward the end of the seasonal blooming. These are about 5 cm in diameter and contain many winged seeds that are easily carried on the wind when the pods split open and disgorge the seeds.
Fruit and foliage of the Kamani Tree.
Calophyllum inophyllum – Kamani, Ball Nut, Alexandria Laurel, Indian Laurel – Introduced by Polynesian colonists to the Hawaiian Islands. The fruit is a round green drupe 3 to 4 cm in diameter and contains a single large round seed. Upon reaching maturity, the fruit is wrinkled and varies in color from yellow to brownish-red. The seeds exude a thick dark-green oil that is still used in the Islands to treat skin irritations and sunburn. It is sought after by cosmetics manufacturers as an ingredient in skin creams. In addition, the combustible fatty acid methyl ester that is an ingredient of the oil is being considered for use in the manufacturing of biodiesel.
Unripened Koa Haole seed pods.
Leucaena leucocephala –Koa Haole – The fruit is an excellent example of a legume (pod). Usually about 10-15 cm long, 2-3 cm wide. It is flat and thin, and dehiscent at both sutures. Produces 15-30 seeds per pod. At maturity it turns dark brown and hardens to brittleness. Considered to be an invasive weed in Hawaii.
Fruit and flower of the Mexican Tulip Poppy.
Hunnemannia fumarifolia –Mexican Tulip Poppy – The long, thin non-fleshy fruit is usually a capsule, breaking open at maturity to release the seeds through pores (poricidal), through the partitions (septae) between the cells, or by means of valves (valvular). They develop a cylindrical, dehiscent fruit, producing many tiny seeds. (about 1 mm long) and black. Naturalized in Hawaii, but is classified as an invasive weed.
The foliage, fruit, and flower of the Pua Kala poppy (Argemone glauca).
Argemone glauca – Pua Kala, Smooth Prickly Poppy – Endemic to Hawaii. Seeds (2-3 mm long) develop in erect prickly dehiscent capsules with as many a seven valves. Once the capsule splits open, the numerous seeds are easily disseminated and sprout rabidly. The seeds contain many alkaloids including protopine (an opiate), sanguinarine (kills skin cells on contact; cause of epidemic dropsy), and berberine (a component of antibiotics).
Fruit (or "berries") of Beach Naupaka.
Scaevola taccada – Beach Naupaka, Hawaiian Half-Flower – Fruit is a round to elliptical fleshy drupe 1-1.7 cm in diameter that turns bright white when mature. The 2-seeded stone is a bit less than 1 cm in diameter. Each plant produces huge quantities of fruit clusters that are easily dispersed by birds and water. Fruits may float for up to one year and remain viable. Plants are able to produce fruit in their first or second year.
The fruit of the ʻOhelo (Vaccinium reticulatum).
Vaccinium reticulatum – ‘Ohelo – Endemic to Hawaii. The edible fruit is usually in the form of a berry, but may also be a drupe. The spiky crown-like calyx persists on the fruit into maturity. The color of the fruit varies widely, but is most often a dark shade of red. Berry is 1-1.5 cm in diameter in diameter and sometimes contains more than 100 of the small brown ovoid seeds. Fruits ripen in 50 to 60 days.
The fruits ("tunas") of a Prickly Pear Cactus.
Opuntia ficus-indica – Prickly Pear Cactus – The fruit (“tuna” or “pears”) of this species is typically greenish white to yellow, yellowish brown, or reddish purple (depending on the strain). Individual fruits are fleshy and barrel-shaped, and at maturity are about 10 cm long and half that wide. Like the pads, the tasty pears possess glochids in their aureoles and so must be carefully handled and properly prepared prior to consumption. Seeds are dispersed by birds, feral pigs, and lizards that feed on the fruits. The seeds from intact fruits and animal droppings germinate after long rainy spells followed by months of hot weather. However, seeds in the soil can remain viable for several years. Vegetative reproduction is accomplished by cladodes (flattened succulent segments and stems) falling close to parental plants and quickly taking root. The latter form of reproduction often results in dense stands of many large plants.
Unripened Papaya (Carica papaya) fruit.
Carica papaya – Papaya – Incorrectly referred to as a “tree”, the plant is actually a large herb. This species displays a lot of variation in the gender of individual plants (in both wild and domesticated strains), as well as the shape and character of its fruit. Usually the fruit is melon-like, oval to nearly round, or elongated and club-shaped. Dimensions of the fruit range from 15-50 cm long and 10-20 cm in diameter. A single fruit can weigh as much as 20 lbs (9 kg). Semi-wild (naturalized) plants produce miniature fruits 2.5-15 cm) long. The fruit is a large berry colored whose yellow to greenish-orange (at maturity) outer skin is thin but relatively tough and waxy in texture. The thick (2.5-5 cm), sweet-tasting, and juicy flesh is attractively orange-colored in cultivars. When the fruit is green and hard it is laden with white latex. The numerous small (5 mm long) black seeds are each coated with gelatinous membrane (aril) and are attached to the inner wall of the flesh of the fruit by a delicate fibrous strand of tissue.
Fruit of the Shoebutton Ardesia.
Ardisia elliptica – Shoebutton Aredisia – A prolific invasive species in Hawaii. Fruits are drupes that initially turn red as they begin to mature, then turn deep purple or black when fully mature. The pulp of the fruit turns the skin of ones fingers purple. Seeds are spherical and about 5 mm in diameter. High seed viability (at least 99 percent) and dissemination of seeds by fruit-eating birds and mammals promotes rapid spread of the seeds across a landscape. Adult plants can set fruit successfully under conditions of full shade or partial sunlight.
Fruit and foliage of the Silversword.
Argyroxiphium sandwicense ssp. macrocephalum – Silversword, ‘ahinahina – Endemic to Hawaii, occurring only on the islands of Maui and Hawaii in a very localized distribution above 1,500 m (4,900 ft) in elevation in alpine deserts. The Silversword is a member of the family Asteraceae, which includes sunflowers; it produces seeds in numerous flower heads in the same way as other sunflowers. After twelve to fifty years, the Silversword produces a five-foot-tall stalk from its center covered with hundreds of flowers (3 cm in diameter) that produce seeds for the next generation. An individual plant only produces seeds once. Once all of the seeds have been shed, the entire plant dies.
Ti Plant (Cordyline terminalis) berries.
Cordyline fruticosa – Ti Plant, Ki – Although it is not native to Hawaii, C. fruticosa is present in the Hawaiian Islands as a feral weed introduced by Polynesian settlers. It produces long panicles of small yellowish to red flowers that mature into red berries. In Hawaii, the starch-rich rhizomes (roots) are fermented and distilled to make okolehao, a notoriously potent liquor.
Fruit and foliage of the Christmas Berry.
Schinus terebinthifolius – Christmas Berry – The fruit is a small (5 mm in diameter) red spherical drupe that is produced in dense clusters of hundreds of fruits. The glossy fruits are initially green, turning bright red when ripe. The tiny (0.3 mm in diameter) seeds are dark brown. Birds and mammals are the primary mechanisms for dispersal, although seeds may be transported via flowing water. Seeds are viable for up to 2 months. Germination is improved by scarification of the seeds; acids in an animal’s digestive tract provide adequate scarification required for germination.
