text: Jamie Taggart, from Argyll and Bute, failed to return from a plant-hunting trip to the northern mountainous area.
  He has not been seen since 2 November, when his rucksack and passport were found at a guest house in Sapa.
  Mr Taggart, 41, runs Linn Botanic Gardens in the village of Cove on the Rosneath peninsula and serves the area as a retained firefighter.
  Local police and the British embassy in Hanoi have been informed about his disappearance.
  Friend and fellow botanist Ian Sinclair, who has been liaising with the search parties, said they had been hampered by horrendous weather.
  "The snow is continuing to melt, but there is a massive amount of snow damage to the forest such as collapsed trees," he said.
  "The weather has been horrendous, with snow down to Sapa. This is extremely unusual as Sapa is upper tropical rainforest.
  "A large group from the national park will be doing an intensive search once the snow melts."
  A search due to begin on Tuesday will concentrate on four trails inside the forest of Lai Chau and Lao Cai, he said.
  Family and friends of Mr Taggart in his hometown of Cove have issued an appeal for funds to help cover the cost of the search.
  A Facebook page - Jamie Taggart Search - has also been set up.
  Organisations and individuals have so far raised thousands of pounds, including six-year-old Annie Ferguson of Cove who donated her Â£14.50 savings.
  The botanist's father, Jim Taggart, found out his son was missing when he failed to appear on a scheduled flight home to Scotland on 29 November.
  He had arrived at a guest house in Sapa on 30 October and left on a motorbike taxi to explore the hills.
  On 2 November his rucksack and passport were found at the accommodation.
  Dr Taggart previously told BBC Radio Scotland that he had received a handful of text messages from his son before contact stopped.
  "I don't think he had got lost. Either something happened to him on his first day on the hills or there is some explanation we can only guess at," he said.
  A Foreign and Commonwealth Office spokesman said: "We are still in close contact with the local authorities and are providing consular assistance to the family at this difficult time."
target: The search for a Scots botanist missing in Vietnam is expected to resume later after being abandoned in heavy snow.