Capsule (fruit)
In
Origins and structure
The capsule (
Dehiscence
In most cases the capsule is dehiscent, i.e. at maturity, it splits apart (dehisces) to release the seeds within. A few capsules are indehiscent, for example those of Adansonia digitata, Alphitonia, and Merciera. Capsules are often classified into four types, depending on the type and location of dehiscence (see Simpson Fig 9.41[2] and Hickey & King [3]).
Loculicidal capsules possess longitudinal lines of dehiscence radially aligned with the
(see illustration).Septicidal capsules have dehiscence lines aligned with the sutures of the ovary septa or placentae, that is between the carpels.
Both loculicidal and septicidal capsules split into distinguishable segments called valves. The valves are a part of the
Circumscissile capsules (pyxide, pyxis, pyxidium or lid capsule) have a transverse, rather than longitudinal, dehiscence line, so that the upper part of the capsule dehisces, usually forming a terminal lid (operculum) that opens (see illustration). An example is Plantago. A variant is the Septifragal capsule (valvular capsule) in which the outer walls break away from the septa and (usually axile) placentae as valves.
Poricidal capsules dehisce through pores (openings) in the capsule, as in Papaver, the seeds escaping through these pores.
Examples of other plants that produce capsules include
Specialised capsules
Some dry dehiscent fruits form specialised capsule-like structures. A
A
Nuts
Capsules are sometimes mislabeled as
See also
References
- ^ Chisholm, Hugh, ed. (1911). . Encyclopædia Britannica (11th ed.). Cambridge University Press.
- ^ a b c d e Simpson 2011, Simple fruit types pp.384–386
- ^ Hickey & King 2000, Capsule dehiscence p. 136
- ^ a b Dahlgren, Clifford & Yeo 1985, Fruit p. 15.
- ISSN 0040-0262.
Bibliography
- Simpson, Michael G. (2011). Plant Systematics. Academic Press. ISBN 978-0-08-051404-8.
- ISBN 978-3-642-64903-5. Retrieved 10 February 2014.
- Hickey, Michael; King, Clive (2000). The Cambridge illustrated glossary of botanical terms. Cambridge: ISBN 978-0-521-79401-5.
- Encyclopædia Britannica online
- The seed site