Type of FlowersHippeastrum:
Hippeastrum is a genus of about 90 species and 600+ hybrids and cultivars of bulbous plants in the family Amaryllidaceae, subfamily Amaryllidoideae,native to tropical and subtropical regions of the Americas from Argentina north to Mexico and the Caribbean. Some species are grown for their large showy flowers. For many years there was confusion amongst botanists over the generic names Amaryllis and Hippeastrum, one result of which is that the common name "amaryllis" is mainly used for cultivars of this genus, which are widely used as indoor flowering bulbs. The generic name Amaryllis applies to bulbs from South Africa, usually grown outdoors.
Most Hippeastrum bulbs are between 5–12 cm (2"–5") in diameter and produce two to seven long-lasting evergreen or deciduous leaves that are 30–90 cm (12"–36") long and 2.5–5 cm (1"–2") wide. The flower stem is erect, 30–75 cm (12"–30") tall, 2.5–5 cm (1"–2") in diameter and is hollow. Depending on the species, it bears two to fifteen large flowers, each of which is 13–20 cm (5"–8") across with six brightly colored tepals (three outer sepals and three inner petals) that may be similar in appearance or very different. Some species are epiphytic (H. calyptratum, H. aulicum, H. papilio and H. arboricola) and need good air circulation around their roots. Seedlings will flower in 3 to 5 years. Hippeastrum species are used as food plants by the larvae of some Lepidoptera species including Hypercompe indecisa.
The taxonomy of the genus is complicated. The first issue is whether the name should be Amaryllis. In 1753 Carl Linnaeus created the name Amaryllis belladonna, the type species of the genus Amaryllis. At the time both South African and South American plants were placed in the same genus; subsequently they were separated into two different genera. The key question is whether Linnaeus's type was a South African plant or a South American plant. If the latter, the correct name for the genus Hippeastrum would be Amaryllis. Alan W. Meerow et al. have briefly summarized the debate, which took place from 1938 onwards and involved botanists on both sides of the Atlantic. The outcome was a decision by the 14th International Botanical Congress in 1987 that Amaryllis L. should be a conserved name (i.e. correct regardless of priority) and ultimately based on a specimen of the South African Amaryllis belladonna from the Clifford Herbarium at the British Museum. Thus Amaryllis L. is not the correct name for the South American genus.
The second issue is whether the name should be Leopoldia. In 1821, William Herbert published the genus name Hippeastrum. Earlier, in 1819, he had proposed Leopoldia as a provisional name (nomen provisorium) for the same taxon. Although Leopoldia was subsequently validated (i.e. became the correct name), this was overlooked, and Hippeastrum rather than Leopoldia was used for the genus of New World amaryllids. Following Filippo Parlatore in 1845, the name Leopoldia was used for a genus of grape hyacinth species, allied to Muscari. In order to preserve the widespread usage of both Hippeastrum and Leopoldia, Fabio Garbari and Werner Greuter proposed in 1970 that Herbert's Hippeastrum and Parlatore's Leopoldia should be conserved and Herbert's Leopoldia rejected. This was accepted and Hippeastrum Herb. is now a conserved name (nomen conservandum), i.e. the correct name regardless of the fact that it does not have priority over Leopoldia. "Hippeastrum" is Greek for "knight's star".While no one is entirely sure why Herbert picked this name, it appears that he was referring to the medieval weapon called a "morning star".
Although the 1987 decision settled the question of the scientific name of the genus, the common name "amaryllis" continues to be used differently. Bulbs sold as amaryllis and described as "ready to bloom for the holidays" belong to this genus (Hippeastrum). "Amaryllis" is also used in the name of societies devoted to the genus Hippeastrum. Different common names are used for the genus Amaryllis, e.g. "naked lady".