When I mow the Dandelions in my lawn they have stems about 6 inches long.  The flowers produced the next, and following days, are very short.  They appear to know the height of the mower and don't extend past that point.  This appears to be a type of learning in a plant since some of the future flowers surely are just a few cells at the time I mowed their parent's heads off (with considerable satisfaction, by the way).

Daffodils and crocuses are always the first flowers I see come spring in New England.  What about them makes them best suited for early spring blooming? Is it the bulb? Or the are the flowers better for colder temperatures?

I have heard of animal that eat plants, and I have heard of animals that eat animals, and I have heard of plants the eat animals, but are there any plants that eat other plants?

Gurvinder Bhandal,

15,  Daventry, UK

It was about 300 mm long. One shot shows it cut open. If it is a plant, it was not obvious which was the attached end.

eg possibly they would gain from the contents of vomit - spreading the spores. this would presumably apply only to the ones that look 'innocent' (& taste ok).

possibly they would gain from the breakdown of the victim's body - minerals, etc. also maybe contents of vomit - spreading the spores. this would presumably apply only to the ones that look 'innocent' (& taste ok).

What gives chestnut mushrooms their brown colour? The colour can be wiped away, leaving what looks like a standard white mushroom.

Barry Strong, Manchester, UK

I work as a wildlife tour guide in the Scottish Highlands so I travel widely in remote corners of the northern Highlands and islands.

On two occasions in late 2009 I have come across a pile of odd objects (see photos) scattered on the ground. The first time was on a remote island in the Orkneys; the second was a few weeks later at an altitude of around 900 metres in the Cairngorm mountains.

Had they been near a road or habitation I would probably have dismissed them as just some sort of household electronic debris, but in both cases they were miles from anywhere. The pile I found in the Cairngorms was at least a 2-hour walk from any road, track or building.

They appear to have a burnt and pitted charcoal-like solid centre encased in a hard, plastic-like cover. The ones in the Cairngorms also had some small charred battery-like cylinders with them.

Can anybody suggest what they are, and why they ended up in such unexpected locations?

John Poyner, Nethy Bridge, Highland Region, UK

What factors are likely to determine whether a specific plant species bothers to be heliotropic (i.e. track the Sun in its daily East-to-West passage)? For example, the Alpine Buttercup and the Sunflower do, but blades of grass seem to lie at random although, being all leaf, they would seem to have most to gain.

(This question prompted by an ironic Anonymous reply to the question on lime and lemon buoyancy "I think I'll go watch some grass grow now and speculate with friends about why the blades face this way or that", which itself leads to 2 comments: (a) I'm not the one posting to TLW at 03:40; and (b) Since when does TLW accept anonymous postings?)