Família Annonaceae

Algumas pesquisas indicaram o crescente número de consumidores adeptos da graviola, que a consomem deliberadamente acreditando em um "poder curativo" de algumas doenças como o câncer e o Mal de Parkinson. Esse frisson deve-se ao fato de muitos experimentos terem sido realizados in vitro e in vivo em animais cobaias, sem a total comprovação dos efeitos da substância anonacina neles. Em humanos esses experimentos nunca foram realizados, ao menos não oficialmente. Outro uso que alimenta a economia e o comércio é a elaboração de medicamentos utilizados na medicina popular, com ação antifúngica, antimalárica e citostática.

Annonaceae

Annonaceae is the Custard Apple family.
It has over 100 genera with over 2,000 species.

Most are evergreen or deciduous trees with some shrubs. Young shoots are often zigzag.
Leaves, on short stalks, are in 2 ranks, with a simple blade that is pinnately veined.

The usually solitary flowers appear to be axillary or leaf opposed but, due to the way the
    shoots grow are probably terminal.
Flowers can also arise from the trunk which is known as cauliflory.
Some species have bracts at the base of the stalk.

The receptacle (the top of the stalk holding the flower parts) may be enlarged, elevated or flat and there is a
    disk (a disc-like structure at the base of the ovary formed from the receptacle or stamens).

The usually pendulous flowers have a thick, fleshy perianth composed of tepals
    (undifferentiated sepals and petals) or with distinct sepals and petals.
The perianth is usually in 3 whorls of 3 but can be 1 or 2 whorls.

There are up to 100 or more short stamens with the outer ones maturing first.
They are typically spirally arranged.
The anthers open via a longitudinal slit or valve that is directed outwards.
There is an anther appendage and sometimes staminodes (infertile stamens).

The superior ovary can have 10 to 100 or more carpels each with 1-10 ovules.
The carpels are usually separate and spirally arranged.
Each has a short, thick style and a papillate stigma.

To prevent self pollination all (or most of) the flowers are in the staminate phase in the morning and
    the pistillate stage later in the day or the next morning.

The fruit is fleshy with quite large seeds.
Several genera produce edible fruit such as Annona and Uvaria.

Annona muricata guanábana

Probably Annona muricata (also know as soursop or guanabana). Many thanks to gravitywave for helping with identification.

Cherimoya (Annona cherimola)

Members of the family Annonaceae have simple leaves with smooth margins that are alternately arranged in two rows along the stems. The radially symmetrical flowers  are usually bisexual. In most species the three sepals are united at the base. There are six brown, yellow, or greenish petals, many stamens in a spiral, and many pistils, each with a one-chambered ovary containing many ovules. The fruit is a berry. Flowers in some species are borne directly on large branches or on the trunk (cauliflorous). The leaves and wood are often fragrant.

Annona squamosa

The Annonaceae are a family of flowering plants consisting of trees, shrubs, or rarely lianas[3] commonly known as the custard apple family[4][3] or soursop family. With 108 accepted genera and about 2400 known species,[5] it is the largest family in the Magnoliales. Several genera produce edible fruit, most notably Annona, Anonidium, Asimina, Rollinia, and Uvaria. Its type genus is Annona. The family is concentrated in the tropics, with few species found in temperate regions. About 900 species are Neotropical, 450 are Afrotropical, and the remaining are Indomalayan.