Water relations of plants

Whenever measured across a suite of different mountain environments, alpine plants (except those on almost bare rock), were found to be well supplied with water. Again, there is a risk of being misguided by the often brownish aspect, causing a lay person to assume drought. The reality is that

• Stomata stay open day by day during the growing season.
• Alpine plants have more stomata per unit leaf area than lowland plants.
• Most species have stomata not only on the lower leaf side but also on the upper leaf side. A few have "decided" to have stomates on the upper leaf side only (some saxifrages and primulas).

1 - Loiseleuria procumbens (Ericaceae)