Pawpaw Traditional Cache

The Pawpaw is an amazing little tree with a big fruit. It's along Fall Creek in The Cornell Wildflower Garden. Parking at the entrance off Caldwell Rd, near the bridge. Daylight only.

Pawpaw

Asimina triloba, the papaw,  pawpaw, paw paw, paw-paw, or common pawpaw, is a species of Asimia (the pawpaw genus) in the same plant family (the Annonaceae) as the custrard-apple, cherimoya,sweetsop,ylang-ylang and soursop.

The pawpaw is native to the Eastern, Southern, and Midwestern United States and adjacent southernmost Ontario, Canada from New York west to southeastern Nebraska, and south to northern Florida and eastern Texas.

The pawpaw is a patch-forming (clonal) understory tree found in well-drained, deep, fertile bottom-land and hilly upland habitat, with large, simple leaves and large fruits.

The paw paw is the largest edible fruit indigenous to the United States (not counting gourds, which are typically considered vegetables rather than fruit for culinary purposes, although in botany they are classified as fruit).

Names

This plant's scientific name is Asimina triloba. The genus name Asimina is adapted from the Native American (probably Miami-Illinois) name assimin or rassimin through the French colonial asiminier. The epithet triloba in the species' scientific name refers to the flowers' three-lobed calices and doubly three-lobed corollas, the shape not unlike a tricorne hat.

The common name of this species is variously spelled pawpaw, paw paw, paw-paw, and papaw. It probably derives from the Spanish papaya, an American tropical fruit (Carica papaya) sometimes also called “papaw", perhaps because of the superficial similarity of their fruits. (In some parts of the world, such as Australia and New Zealand,the name Paw Paw is commonly used for a variety of Papaya.) Asimina triloba has had numerous local common names including: wild banana, prairie banana, Indiana banana, Hoosier banana, West Virginia banana, Kansas banana, Kentucky banana, Michigan banana, Missouri banana, the poor man’s banana, Ozark banana, and banango.

Description

Asimina triloba is a large shrub or small tree growing to a height of 35 feet (11 m) (rarely to 45 feet or 14 m) with a trunks 8-12 inches (20–30 cm) or more in diameter. The large leaves of pawpaw trees are clustered symmetrically at the ends of the branches, giving a distinctive imbricated appearance to the tree's foliage.

The leaves of the species are simple, alternate and spirally arranged, entire, deciduous, obovate-lanceolate, 10-12 inches (25–30 cm) long, 4-5 inches (10–13 cm) broad, and wedge-shaped at the base, with an acute apex and an entire margin, with the midrib and primary veins prominent. The petioles are short and stout, with a prominent adaxial groove. Stipules are lacking. The expanding leaves are conduplicate, green, covered with rusty tomentum beneath, and hairy above; when fully grown they are smooth, dark green above, and paler beneath. When bruised, the leaves have a disagreeable odor similar to a green bell pepper. In autumn the leaves are a rusty yellow, which make spotting pawpaw groves possible from a long distance.

Pawpaw flowers are perfect, about 1-2 inches (3–5 cm) across, rich red-purple or maroon when mature, with three sepals and six petals. They are borne singly on stout, hairy, axillary peduncles. The flowers are produced in early spring at the same time as or slightly before the new leaves appear, and have a faint fetid or yeasty smell.

The fruit of the pawpaw is a large, yellowish-green to brown berry, 2–6 in (5–16 cm) long and 1–3 in (3–7 cm) broad, weighing from 0.7–18 oz (20–500 g), containing several brown/black seeds 1/2 to 1 in (15–25 mm) in diameter embedded in the soft, edible fruit pulp. The conspicuous fruits begin developing after the plants flower; they are initially green, maturing by September or October to yellow or brown. When mature, the heavy fruits bend the weak branches down.

Other characteristics:

    •    Calyx: Sepals three, valvate in bud, ovate, acuminate, pale green, downy.

    •    Corolla: Petals six, in two rows, imbricate in the bud. Inner row acute, erect, nectariferous. Outer row broadly ovate, reflexed at maturity. Petals at first are green, then brown, and finally become dull purple or maroon and conspicuously veiny.

    •    Stamens: Indefinite, densely packed on the globular receptacle. Filaments short; anthers extrorse, two-celled, opening longitudinally.

    •    Pistils: Several, on the summit of the receptacle, projecting from the mass of stamens. Ovary one-celled; stigma sessile; ovules many.

    •    Branchlets: light brown, tinged with red, marked by shallow grooves.

    •    Winter buds: Small, of two kinds, the leaf buds pointed and closely appressed to the twigs, and the flower buds round, brown, and fuzzy.

    •    Bark: Light gray, sometimes blotched with lighter gray spots, sometimes covered with small excrescences, divided by shallow fissures. Inner bark tough, fibrous. The bark with a very disagreeable odor when bruised.

    •    Wood: Pale, greenish yellow, sapwood lighter; light, soft, coarse-grained and spongy. Sp. gr., 0.3969; weight of cu ft 24.74 lb.

Ecology

Asimina triloba, the pawpaw, commonly grows in floodplains and shady, rich bottomlands, where it often forms a dense, clonal spreading undergrowth in the forest, often appearing as a patch or thicket of individual small slender trees. Pawpaws are not the first to colonize a disturbed site (arriving roughly four years after a clearout), but may become dominant and slow the establishment of oaks and nickories. Although shade-tolerant, pawpaws do not persist in undisturbed old growth forest. Pawpaws spread locally primarily by root suckers; sexual reproduction by seed does also occur, but at a fairly low rate.

Pawpaw flowers are insect-pollinated, but fruit production is sometimes limited as few if any pollinators are attracted to the flower's faint, or sometimes non-existent scent. The flowers produce an odor similar to that of rotting meat to attract blowflies or carrion beetles for cross pollination. Other insects that are attracted to pawpaw flowers include scavenging fruit flies, carrion flies and beetles. Because of irregular fruit production, some believe pawpaw plants are self-incompatible, requiring cross-pollination between trees of different clones (patches).

Yellow-billed cuckoo (Audubon), with foliage and fruits of Asimina triloba

The fruits of the pawpaw are eaten by a variety of mammals, including raccoons, gray foxes, opossums, squirrels, and black bears.

The disagreeable-smelling leaves, twigs, and bark of pawpaws contain natural insecticides known as acetogenins. Pawpaw leaves and twigs are seldom consumed by rabbits, deer, or goats, or by many insects. However, mules have been seen eating pawpaw leaves in Maryland.

Larvae of the zebra swallowtail (Protographium marcellus), a butterfly, feed exclusively on young leaves of Asimina triloba and various other pawpaw (Asimina) species, but never occur in great numbers on the plants. Chemicals in the pawpaw leaves confer protection from predation throughout the butterfly's life, as trace amounts of acetogenins remain present, making them unpalatable to birds and other predators.

Conservation status

On a global (range-wide) scale, the common pawpaw (Asimina triloba) has a NatureServe global conservation rank of G5 (very common).

In the United States, the species has a NatureServe national conservation rank  of N5 (very common), but is considered a threatened species in New York, and an endangered species in New Jersey.

In Canada, where the species is found only in portions of southern Ontario, it has a NatureServe national conservation rank of N3 (vulnerable), and a NatureServe national conservation rank  of S3 (vulnerable) in Ontario. The Ontario Ministry of Natural Resources has given the species a general status of "Sensitive", and its populations there are monitored.

In areas in which deer populations are dense, pawpaws appear to be becoming more abundant locally, since the deer avoid them but consume seedlings of most other woody plants.

Still Life with Pawpaws by Edward Edmondson, Jr., c. 1870-75

History

The earliest documented mention of pawpaws is in the 1541 report of the Spanish de Soto expedition, who found Native Americans cultivating it east of the Mississippi River. The Lewis and Clark Expedition consumed pawpaws during their travels. Chilled pawpaw fruit was a favorite dessert of George Washington and Thomas Jefferson planted it at Monticello, his home in Virginia.

Cultivation

In cultivation, lack of successful pollination is the most common cause of poor fruiting. Cross-pollination of at least two different genetic varieties of the plant is recommended, and growers often resort to hand pollination or to use of pollinator attractants such as spraying fish emulsion or hanging chicken necks or other meat near the open flowers to attract pollinators. While pawpaws are larval hosts for the zebra swallowtail butterfly, these caterpillars are usually present only at low density, and not detrimental to the foliage of the trees.

Pawpaws have never been cultivated for their fruits on the scale of apples or peaches, primarily because pawpaw fruits ripen to the point of fermentation soon after they are picked, and only frozen fruit will store or ship well. Other methods of preservation include dehydration, production of jams or jellies, and pressure canning (using the numerical values for bananas).

In recent years, cultivation of pawpaws for fruit production has attracted renewed interest, particularly among organic growers, as a native fruit with few to no pests, successfully grown without pesticides. The commercial cultivation and harvesting of pawpaws is strong in southeastern Ohio and also being explored in Kentucky and Maryland, as well as various areas outside the species' native range, including California, the pacific Northwest, and Massachusetts.

The pawpaw is also gaining in popularity among landscapers and backyard gardeners because of the tree's distinctive growth habit, the appeal of its fresh fruit, and its relatively low maintenance needs once established. However, only container-grown pawpaws should be transplanted; use of bare-rooted pawpaws is not recommended, since their fragile root hairs tend to break off unless a cluster of moist soil is retained on the root mass.

Habitat restoration

Pawpaws are sometimes included in ecological restoration plantings since this tree grows well in wet soil and has a strong tendency to form well-rooted colonial thickets. The pawpaw is particularly valued for establishing fast-growing vegetation in areas where frequent flooding might produce erosion, since their root systems help hold streambanks steady.

Uses

Fruits

Asimina triloba is often called wild banana or prairie banana because of its banana-like creamy texture and flavor.

As described by horticulturist Barbara Damrosch, the fruit of the pawpaw "looks a bit like mango, but with pale yellow, custardy, spoonable flesh and black, easy-to-remove seeds.” Wild-collected pawpaw fruits, ripe in late August to mid-September, have long been a favorite treat throughout the tree's extensive native range in eastern North America, and on occasion are sold locally at farmers’ markets. Pawpaw fruits have a sweet, custardish flavor somewhat similar to banana, mango, and cantalope, varying significantly by source or cultivar, with more protein than most fruits. Nineteenth-century American agronomist E. Lewis Sturevant  described pawpaws as

... a natural custard, too luscious for the relish of most people

Ohio botanist William B. Werthner noted that

The fruit ... has a tangy wild-wood flavor peculiarly its own. It is sweet, yet rather cloying to the taste and a wee bit puckery – only a boy can eat more than one at a time.

Fresh fruits of the pawpaw are commonly eaten raw, either chilled or at room temperature. However, they can be kept only 2–3 days at room temperature, or about a week if refrigerated. The easily bruised pawpaw fruits do not ship well unless frozen. Where pawpaws grow, the fruit pulp is also often used locally in baked dessert recipes, with pawpaw often substituted with volumetric equivalency in many banana-based recipes. Pawpaws may also be blended into ice cream or included in pancakes.

Due to its potential toxicity and pesticidal activities, pawpaw consumption may be harmful to humans.

Zebra swallowtail butterflies (Eurytides marcellus) with pawpaw foliage

The cache is a tied in, camoed, small, "small", pill bottle. This one has a tab on the bottle that you have to push down while you screw to open it. Make sure it clicks when you close it. Please BYOP and keep track of the rubber band and the plastic bag when you sign the log. Yes, I know you have only two hands and you have to hold on to the lid as well. A finger for the rubber band and pockets for the rest works for me.

The cache had to be moved because it was too close to another. Now you have to go beyond the Pawpaw, on the trail you see in the picture "GZ Trail", a bit further along the creek to the new GZ."