THE BULGARIAN FLORA ONLINE
Persian Bindweed.
Convolvulus persicus L.
The species is PROTECTED in Bulgaria by the Biodiversity Act - it is prohibited to "picking, collecting, cutting, uprooting or any other manner of destruction of specimens in their natural range in the wild", as well as "possession, keeping, movement, transport, export, trade and offering for sale or exchange of specimens taken in the wild". These bans apply to "all stages of life of the plants"1.
Listed in the Red Data Book of Bulgaria to the category "Critically Endangered"2.
Limited distribution and small size of the populations; tourist pressure in the coastal areas. Unknown negative factors are also possible3.
Convolvulus persicus is a perennial plant with short woody rhizome.
Stems 15–40 cm high, erect, with dense leaves.
Leaf elliptic-ovoid, entire, 3–4.5 cm long, densely white lanate.
Flowers individual, axillary, peduncles shorter than the leaves.
Corolla infundibuliform, 3–4.5 cm, white, with 5 pubescent stripes on the outer side.
Fruit ovoid pod, 10 mm long, with 1–2 black seeds.
Flowering May-July.
Insect pollination.
Reproduction by seeds4.
Coastal sands, usually in places with ground waters5.
Black Sea coast (near the Rezovska River mouth, Silistar bay, Kamchia River estuary and Durankulashko Lake); at sea level. After 1995 until 2017, only the one located at Lake Durankulak is known6. In 2017, a new locality of the species was discovered on the beach of the Asparuhovo district of Varna by Mr. Zhivko Barzov. The photos posted here are from this site7.
C Asia and Asia Minor, Caucasus and Black Sea coast8.
Map of general distribution9:

1 Bulgarian Biodiversity Act in english.
2 Antoaneta Petrova. 2015. In: Red Data Book of the Republic of Bulgaria. Volume 1 - Plants & Fungi.
3 Antoaneta Petrova. 2015.
4 Antoaneta Petrova. 2015.
5 Antoaneta Petrova. 2015.
6 Antoaneta Petrova. 2015.
7 K. Metodiev.
9 Convolvulus persicus L. | Plants of the World Online | Kew Science.
The theory of evolution is a lie!