A very special entry today, from my perspective. It is rare that both the photographs / illustrations and text for Botany Photo of the Day are contributed by someone not from UBC, so I really appreciate the effort by both writer Joseph Beaujean of the Jardin botanique de Liège and translator Alain Vanderpoorten of the Université de Liège in Belgium for today's entry. Joseph writes:

Wallonia, and especially the Liège province, includes among its botanical highlights a rare endemic plant, "Joubarbe d'Aywaille". The taxon is known from a single locality, the Heid des Gattes in Aywaille, in the Amblève valley between Soa and Sougné-Remouchamps.

Dr A. L. S. Lejeune (1779-1858), from Verviers, was the first to mention the taxon in 1813 in the Supplément de la Flore de Spa (p. 310), where one can read: Sempervivum montanum minus Decand. "Se trouve sur les rochers près de Sougné". Between 1825 and 1830, Lejeune and Courtois edited the Choix de plantes de la Belgique. In the 15th issue published in 1829; this endemic plant from Aywaille appears under the name Sempervivum montanum L.

The status of the taxon remained unchanged until 1873 when, following a meeting of the Botanical Society of France held in Belgium, Edouard Morren (1833-1886), a professor at University of Liège famous for his works on the Bromeliaceae, publishes a note about the botanical history in the Liège area and the Aywaille Sempervivum. In 1873, he also publishes (in the journal La Belgique Horticole), a second note including two colour figures (today's illustrations), wherein he describes the taxon as new variety of Sempervivum funckii, that is, Sempervivium funckii var. aqualiense.

Bibliography:

• Morren E., 1873. - Note sur la joubarbe d'Aywaille. Sempervivum funckii Br. var. aqualiense. La Belgique Horticole 23:161-166
• Lambinon J., 1985. - n° 11280 - Sempervivum funckii F. Braun ex Koch var. aqualiense E. Morren. Soc. Ech. Pl. Vasc. Eur. Bass. Médit., Bull. 20:46-47 (Notes brèves sur certaines centuries distribuées dans le fascicule 20)
• Beaujean J., 1997. - La joubarbe d'Aywaille. Une plante protégée par la loi ... menacée de destruction volontaire. Revue Verviétoise d'Histoire Naturelle. Printemps 1997: 7-12
• Lambinon J., Delvosalle L., Duvigneaud J. & coll., 2004. - Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes), 5ème éd. Meise, Ed. Patr. Jard. Bot. Nat. Belg., CXXX + 1167 p. (cf. 208-309).