Helene Alice Jacottet was a sister of Reverend Edouard Jacottet, a missionary who worked in Lesotho, and of Dr Lautre Jacottet, a medical practitioner who worked with the Paris Evangelical Mission in Lesotho and East Griqualand. Helene collected plants from about 1905 to 1914 in East Griqualand (at Mafube Mission near Matatiele, and elsewhere) and in Lesotho around Sehlabathebe (near the south-eastern border), along the Fika le Motho River in the eastern highlands, and on the other side of the country at Morija and Masite (some 30 km south of Maseru) and Roma (about 30 km south-east of Maseru). She was one of the first to collect plants in the high mountains of Lesotho. Some 1000 sheets of her specimens were sent to Zurich and Geneva, labelled as collected by her brother Lautre and herself, though she probably collected most or all of them. Some confusions of localities and dates under the same number occur. Several species were named in her honour, including Rhynchosia jacotteti, Senecio jacottetianus, Satyrium jacottetiae, Chaenostoma jacottetianum, and Dipcadi helenae.