Quelques articles :

• Ravenna, P. 1988. Studies in the genus Stenomesson (Amaryllidaceae). Onira, Botanical Leaflets, 1(2): 17-21.
• Ravenna, P. 1988. New species of South American Habranthus and Zephyranthes (Amaryllidaceae). Onira, 1(8): 53-56.
• Ravenna, P. 1999. New species of Zephyranthes and Habranthus (Amaryllidaceae): I. Onira, 3(16): 52-61.
• Ravenna, P. 1999. New species of Zephyranthes and Habranthus (Amaryllidaceae): II. Onira, 3(17): 62-67.
• Ravenna, P. 2000. Five new species in the genus Griffinia (Amaryllidaceae). Onira, 4(5):19-22.
• Ravenna, P. 2000. ?. Onira, 4(7): ?. (Hieronymiella ferruginea p25, H. angacoana p26, sect. Synexa p27)
• Ravenna, P. 2000. Tocantinia and Cearanthes, two new genera, and Tocantinieae new tribe, of Brazilian Amaryllidaceae. Onira, Bot. Leafl. 5(3): 9-12.
• Ravenna, P. 2001. Sternbergia minoica a new species of Amaryllidaceae from Greece. Onira, 5(10): 39-41.
• Ravenna, P. 2001. Hieronymiella vittata, a new species of Amaryllidaceae from northern Argentina. Onira, 5(10): 50-51.
• Ravenna, P. 2001. Hieronymiella angustissima, an additional new species of Amaryllidaceae from north Argentina. Onira, 5(13): 62-63.
• Ravenna, P. 2001. New species of Zephyranthes and Habranthus (Amaryllidaceae): III. Onira, 6(5): 38-43.
• Ravenna, P. 2002. New Rauhia species from northern Peru (Amaryllidaceae). Onira, 7(4): 11-12.
• Ravenna, P. 2003. Eidema, a new genus of neotropical Amaryllidaceae. Onira, Bot. Leafl., 8(1): 1-4.

Contact : Ravenna, bot_leaf_onira [at] yahoo.co.uk