Fruit ID #7

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Fruit Identification Photos #8

Unusual Fruits Called Capsules

Sweet Gum, Cape Chestnut, & Nigella

The capsule is a dehiscent dry fruit that splits open is various ways and usually along several definite seams. Capsules typically split open into well-defined sections or carpels which represent modified leaves. This is a very common dry fruit found in many different plant families. E.g. Catalpa, Jacaranda, Pittosporum, Aesculus, Agave, Yucca, Eucalyptus, devil's claw (Proboscidea), floss silk tree (Chorisia), kapok tree (Ceiba) and castor bean (Ricinus communis). Capsules may split open along the locules (loculicidal), along the septa (septicidal), through pores (poricidal), or the entire top of the capsule separates as a single lid-like section (circumscissle). A common landscaping tree in southern California called the golden-rain tree (Koelreuteria) produces bladder-like capsules that are loculicidally dehiscent into three valves. The opium poppy (Papaver somniferum) produces a classic poricidal capsule in which the tiny seeds fall out of the pore-like windows as the capsule shakes in the wind. The edible weed called purslane (Portulaca) has a many-seeded circumscissle capsule. The Mexican jumping bean (Sebastiana pavoniana) produces a 3-carpellate capsule, each carpel bearing a seed. Sometimes the carpel is occupied by a special moth larva that eats the seed and moves its one-room carpel container by contorting and hurling its body.

In the sweet gum (Liquidambar styraciflua) the globose fruiting heads are composed of numerous tiny capsules, each bearing one or two winged seeds and a number of aborted ovules (immature seeds). Sweet gum belongs to the witch hazel family (Hamemelidaceae) along with the infamous witch hazel (Hamemelis virginiana). The seed capsules of witch hazel contain two black seeds which are forcibly ejected with a poping sound when the capsule is mature and dry.

Witch-Hazel Family (Hamemelidaceae)

The fruits of liquidambar or sweet gum (Liquidambar styraciflua) are composed of a spherical cluster of small capsules, each capsule with a sharp-pointed style and a pericarp bearing one or two tiny winged seeds. This shade tree is native throughout the eastern and midwestern United States. It is commonly planted in southern California for its beautiful crimson foliage during the late fall.

Capsule Cluster Of Liquidambar Tree
See Circumscissle Capsule Of Purslane
See Exploding Capsules Of Witch Hazel
See Article About Mexican Jumping Beans
Devil's Claws: Amazing Hitchhiking Capsules
Opium Poppy Capsule: Source Of Raw Opium

Citrus Family (Rutaceae)

Seed capsule of the cape chestnut (Calodendron capense), an evergreen flowering tree native to South Africa. The woody capsule is composed of five carpels, each with a large, shiny black seed. The carpels are covered with pointed (tuberculate) projections. Many species in the citrus family (Rutaceae) have a fleshy fruit called a hesperidium (e.g. orange, lemon and grapefruit). The classification of cape chestnut in the citrus family is based largely on floral characteristics, rather than type of fruit.

Fragrant flowers of the cape chestnut (Calodendron capense)

Buttercup Family (Ranunculaceae)

The unusual seed capsule of "love-in-a-mist" (Nigella damascena), a European wildflower that is commonly cultivated in the United States. The capsule is composed of five fused carpels (syncarpous), each with a long, erect style, the entire structure surrounded by the filiform divisions of the upper involucral leaves. This type of fruit is unusual for the buttercup family because many species are apocarpous with three to five separate carpels that become seed-bearing follicles.

See Unusual Flower Of Live-In-The-Mist (Nigella)

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