rostellum

American  

[ro-stel-uhm] / rɒˈstɛl əm /

noun

• rostella
  plural

1. Biology. any small, beaklike process.

2. Botany. a beaklike modification of the stigma in many orchids.

3. Zoology.

   1. a projecting part of the scolex in certain tapeworms.

   2. a part of the mouth in many insects, designed for sucking.

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rostellum British  

/ rɒˈstɛləm /

noun

1. biology a small beaklike process, such as the hooked projection from the top of the head in tapeworms or the outgrowth from the stigma of an orchid

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Other Word Forms

Derived Forms

• rostellate
  adjective

Inflected Forms

Nouns

• rostella
  plural

Etymology

Origin of rostellum

1750–60; < New Latin; Latin: little beak, snout, diminutive of rōstrum snout ( see rostrum); for formation, see castellum

Example Sentences

See Examples For:

rostellum

I have been much interested by what you say on the rostellum exciting pollen to protrude tubes; but are you sure that the rostellum does excite them?

From More Letters of Charles Darwin — Volume 2 by Sir Francis Darwin

I did think it possible or probable that perfect fertilisation might have been effected through rostellum.

From More Letters of Charles Darwin — Volume 2 by Sir Francis Darwin

It is to discover whether rostellum yet retains some of its primordial function of being penetrated by pollen-tubes.

From More Letters of Charles Darwin — Volume 2 by Sir Francis Darwin

I have asked Asa Gray for seeds, to whom I have mentioned your observations on rostellum, and asked him to look closer to the case of Gymnadenia.

From More Letters of Charles Darwin — Volume 2 by Sir Francis Darwin

In Gymnadenia tridentata, according to Asa Gray, the anther opens in the bud, and the pollen being somewhat coherent falls on the stigma and on the rostellum which latter is penetrated by the pollen-tubes.

From More Letters of Charles Darwin — Volume 2 by Sir Francis Darwin