Hippeastrum
Hippeastrum is a genus of 116 species, and over 600 hybrids and cultivars, of perennial, herbaceous and bulbous plants, native to tropical and subtropical regions of the Americas, from Mexico south to Argentina and on some islands in the Caribbean. The majority have large, fleshy bulbs and tall, broad, strap-like leaves that are evergreen, and large red or purple flowers. Numerous colors and cultivars have been created over the past hundred years.
Hippeastrum is a genus in the family Amaryllidaceae. For many years, there has been confusion among botanists, as well as collectors and the general public, over the generic names Amaryllis and Hippeastrum; the former is a South African genus of plants, while the latter is a new world genus. However, the common name "amaryllis" has been used for Hippeastrum for years, especially for the ornamental cultivars. Within the genus Hippeastrum exist many epiphytic species, as well, which may be found living in natural debris and leaf litter on the crooks of tree branches; by comparison, Amaryllis is a primarily terrestrial, southern African genus of perennial bulbs.
Description
Most Hippeastrum bulbs are tunicate. The bulbs are generally between 5-12 cm in diameter and produce two to seven long-lasting evergreen or deciduous leaves that are 30-90 cm long and 2.5-5 cm wide. The leaves are hysteranthous, sessile, rarely persistent and subpetiolate.The flowers are arranged in umbelliform inflorescences which are pauciflor or pluriflor, supported on an erect hollow scape which is 20-75 cm tall and 2.5-5 cm in diameter with two free bracts forming a spathe which is bivalve with free leaflets at its base.
Depending on the species, there are two to fifteen large showy flowers, which are more or less zygomorphic and hermaphrodite. Each flower is 13-20 cm across, and the native species are usually purple or red. They are funnelform and declinate in shape. The perianth has six brightly colored tepals that may be similar in appearance or very different. The perianth segments are subequal or unequal. The tepals are united at the base to form a short tube, usually with a rudimentary scaly paraperigonium with fimbriae or a callose ridge present at the throat.
The androecium consists of six stamens with filiform filaments, which are fasciculate and declinate or ascendent. The anthers are dorsifixed or versatile. In the gynaecium, the ovary is inferior and trilocular with pluriovulate locules. The style is filiform, and the stigma trifid. The fruit forms a trivalve capsule containing seeds which are dry, flattened, obliquely winged or irregularly discoid, hardly ever turgid, and globose or subglobose, with a brown or black phytomelanous testa.
Etymology
The name Hippeastrum was first given to the genus by Herbert, being derived from the Ancient Greek, meaning a "knight's star" from ἱππεύς and ἄστρον, to describe the first recognized species, Hippeastrum reginae. Herbert proposed to call the genus, which he distinguished from Linnaeus' Amaryllis, Hippeastrum, or "knight's-star-lily". He states;"I have named Hippeastrum or Knights-star-lily, pursuing the idea which gave rise to the name Equestris".
Herbert's fourteen species included this Hippeastrum equestre. This 'equine' connection refers to Carl Linnaeus the Younger who had named a West Indian species as Amaryllis equestris, because of its similarity to the African genus Amaryllis. This name and attribution was first published by William Aiton in 1789, in his Hortus Kewensis. Which species this was is not known precisely. However, in 1795 William Curtis, described Amaryllis equestris or the Barbados lily in his Botanical Magazine, referring to Aiton:
In 1803 John Sims claimed Curtis had made a mistake in this attribution, and that;
"this name was given from the remarkable likeness the front view of it has to a star of some of the orders of knight-hood; an appearance well expressed by JACQUIN's figure in the Hortus Schoenbrunnensis"
Despite much speculation, there is no definitive explanation of either Linnaeus fils or Herbert's thinking. For instance the 'knight's star' has been compared to Linnaeus' decoration as a Knight of the Order of the Polar Star. The Latin word equestris may have been confused with equi, or possibly Herbert was making a literary knight's move on the Linnaean term. The flower name has even been compared to the mediaeval weapon, the spoked mace or Morning Star which it superficially resembles.
Common name
Although the 1987 decision settled the question of the scientific name of the genus, the common name "amaryllis" continues to be used. Bulbs sold as amaryllis and described as ready to bloom for the holidays belong to the genus Hippeastrum. "Amaryllis" is also used in the name of some societies devoted to the genus Hippeastrum. Separate common names are used to describe the genus Amaryllis, e.g., "Naked Lady".Taxonomy
Separation of ''Hippeastrum'' from ''Amaryllis''
The taxonomy of the genus is complicated. The first issue is whether the name should more properly be Amaryllis L.. In 1753 Carl Linnaeus created the name Amaryllis belladonna, the type species of the genus Amaryllis, in his Species Plantarum along with eight other Amaryllis species. Linnaeus had earlier worked on the Estate of George Clifford near Haarlem between 1735 and 1737 describing the plants growing there in his Hortus Cliffortianus in 1738. It is to this work that he refers in his Species Plantarum. This was assumed to be the South African Cape Belladonna, although not precisely known. Clifford's herbarium is now preserved at the Natural History Museum in London.At the time both South African and South American plants were placed in this same genus. By the early nineteenth century Amaryllis had become a polymorphic genus with about 50 species from what we would consider a dozen genera today, and attempts were made to separate it into different genera. This work commenced in 1819 with the contributions of the English botanist, the Revd. William Herbert in Curtis's Botanical Magazine which he expanded in 1821 in The Botanical Register, identifying 14 species of the new genus of Hippeastrum, and only leaving three species in Amaryllis. The rest of the Amaryllis species he transferred to other genera, several of which he created. Herbert further refined his descriptions of Hippeastrum in his work on the Amaryllidaceae in 1837.
Nomenclature debate
Since then, a key question has been whether Linnaeus's original type was a South African plant or a South American plant. If the latter, the correct name for the genus Hippeastrum would then be Amaryllis and a new name would need to be found for the South African genus. In 1938 Johannes Cornelius Theodorus Uphof claimed, with some evidence, that the plant was in fact the South American Hippeastrum equestre Herb. a plant which Carl Linnaeus' son, Linnaeus the Younger had described c. 1781-83 but soon after appearing in the Hortus Kewensis of 1789. This paper sparked a debate over the next half century, that delayed the official transfer of species from Amaryllis to Hippeastrum. This debate involved botanists on both sides of the Atlantic and the outcome was a decision by the 14th International Botanical Congress in 1987 that Amaryllis L. should be a nomen conservandum and ultimately based on a specimen of the South African Amaryllis belladonna from the Clifford Herbarium. Thus Amaryllis L. is the correct name for the South African genus, not the South American genus.Claim for ''Leopoldia''
The second issue is whether the name should be Leopoldia. In 1819 Herbert had proposed Leopoldia as a nomen provisorium for the same taxon as he called Hippeastrum in 1821. Although Leopoldia was subsequently validated, 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 nomen conservandum, i.e., the correct name regardless of the fact that it does not have priority over Leopoldia.Intergeneric hybrids
While interspecific hybrids of Hippeastrum are relatively common, hybridization with other genera of Amaryllidaceae are more rare. The most conspicuous exception is the hybrid obtained through crossbreeding with the Mexican Sprekelia formosissima, another member of the tribe Hippeastreae, originally called Amaryllis formosissima, which is apomictic. × Hippeastrelia is the name given to this cross.Subgenera
A number of subgenera have been proposed over the years. For instance in the 1870s and 1880s John Gilbert Baker considerably reorganised Hippeastrum. In 1878 he described nine sections of the genus, but by 1888 he included seven subgenera, namely Habranthus, Phycella, Rhodophiala, Macropododastrum, Omphalissa, Aschamia and Lais, some of which have since been treated as separate genera. Baker both reduced the original number of species of Herbert, but also enlarged the genus by adding in other genera such as Habranthus, Phycella, Rhodophiala and Rhodolirion, which he included as separate sections of Hippeastrum. In addition, he included many new species being discovered in South America, particularly Chile. His 1878 classification included 47 species, reduced to 38 by 1888. These subgenera were not widely used due to indistinct boundaries of some of the divisions. For reference, these were:- Aschamia Baker
- Cephaleon Traub
- Lais Baker
- Macropodastrum Baker
- Omphalissa Baker
- Sealyana Traub
- Hippeastrum subg. Tocantinia Nic.García
- Hippeastrum subg. ''Hippeastrum''