Silene gazulensis is a species of plant in the family Caryophyllaceae. It is endemic to Cádiz, Spain. Its natural habitat is rocky areas. It is threatened by habitat loss. This rare cushion-forming plant produces delicate white flowers that bloom among the limestone rocks of southern Spain. Known locally as the Gazules campion, it forms small mounded clusters rarely exceeding 10 cm in height, with its woolly, spoon-shaped leaves arranged in rosettes that help it survive in its harsh rocky habitat.
Silene gazulensis is a low, cushion-forming perennial herb () that rarely exceeds 10 cm in height. Its stems are woody and bear scars from previous seasons' leaves, while most foliage arises in a basal rosette. The leaves are spoon-shaped to narrowly lance-shaped, measuring 20âÂÂ70 mm long and 6âÂÂ16 mm wide, and are densely (covered in matted, woolly hairs) with non-glandular hairs up to 0.3 mm long on the blade and 0.7 mm on the .
Flowering stems () reach up to 6 cm and terminate in a tightly contracted bearing 6âÂÂ11 flowers, each subtended by bracts (5âÂÂ11 mm) and smaller (4âÂÂ8 mm). Individual flowers are borne on very short of 1âÂÂ3 mm. The at is a slender cylinder 15âÂÂ20 mm long and 4âÂÂ6 mm wide, with ten prominent often tinged purple towards the tip. It ends in five blunt teeth, 1âÂÂ1.5 mm long, edged with a membranous margin and fringed with fine hairs; the entire calyx surface bears non-glandular, (warty-surfaced) hairs up to 0.3 mm long. The corolla spans 14âÂÂ20 mm in diameter and comprises five two-lobed that are whiteâÂÂoccasionally flushed with pink on the reverseâÂÂeach up to 10 mm long. The corolla throat is about 2.5 mm deep and bears an inconspicuous . Reproductive structures include ten and a green topped by three white , all borne on a pubescent 6âÂÂ8 mm long. Fruit is an ovoid capsule (9âÂÂ11 mm by 5âÂÂ7 mm), matching the calyx in length. Seeds are kidney-shaped (), grey, 1.1âÂÂ1.5 mm long and 0.9âÂÂ1.1 mm wide, laterally flattened with flat faces and a grooved, (wart-covered) back.
Silene gazulensis was formally described in 1999 by Galán de Mera and colleagues and assigned to Silene section Siphonomorpha, a lineage of cushion-forming campions with slender, veined calyces and often woolly, non-glandular hairs. Section Siphonomorpha is centred on the western Mediterranean, where its taxa inhabit rocky, calcium-rich substrates. The species epithet gazulensis honours its type locality at Alcalá de los Gazules in Cádiz, Spain. Morphologically, S. gazulensis differs from the widespread S. andryalifolia and the Gibraltar endemic S. tomentosa by its low, (cushion-like) growth, white petals (rather than pale violet), and a narrowly cylindrical calyx bearing verruculose (warty-surfaced) hairs without stalked glands.
Molecular analysis of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA shows that S. gazulensis shares 98.2 % sequence identity with S. tomentosa and 96.7 % with S. andryalifolia, placing it squarely between these two taxa in genetic affinity. Cytogenetic comparisons also support its distinct status, with chromosome characters that reinforce its recognition as a separate species rather than a mere variant or hybrid form.