Hippeastrum is a genus in the family Amaryllidaceae with about 70-90 species and 600+ hybrids and cultivars. The genus is native to tropical regions of the Caribbean, Mexico but mostly South America. There are two centers of diversity, one in eastern Brazil (origin of the genus) and the other in the central Andes along the Peru and Bolivia border (14-15°S and 68-70°W). Within this area, the highest concentration is in the Biogegráfica Province of Los Yungas Peruvian-Bolivian between 750-2800 m.
In 2021 the PBS published the first monograph The Genus Hippeastrum in Bolivia by Raúl F. Lara Rico Roberto Vásquez Chávez and Margoth Atahuachi Burgos.
Hippeastrum means "knight's star" from hippeus, meaning a horseman or knight. Herbert, who named the genus called it "knight's star lily". Because at one point it was part of the genus Amaryllis, these plants are still erroneously called Amaryllis. This is especially true in hybrids because the horticultural trade has not made efforts to call these plants by their correct names (and perhaps this would not even be possible). Both genera have large ground-level bulbs and strap-like leaves, but Hippeastrum has hollow stems and Amaryllis has massive stems. Amaryllis is summer-dormant and blooms in fall, before the leaves emerge. The flowers are in shades of pink and white, and the seeds are fleshy pink or white pea-sized spheres. Hippeastrum species are generally evergreen or winter-dormant, and many bloom with the leaves present. Flower colors vary from white to greenish yellow to reds and oranges. The seeds are black or brown, thin and papery, and will often float on water.
Flowering time was discussed on the PBS list, mostly it is when the bulbs break dormancy and grow leaves in the Spring.
In some parts of the United States people have had success planting out in the garden bulbs that have been forced.
Cultivation of these plants have been well documented and cultivation through seeds have been discussed thoroughly on the PBS forum. Seeds have short viability but no loss of viability had been observed after 4 months. Because of this short viability period seeds should be sown as soon as possible. There are two basic method to sowing seeds. One method is direct sowing, either into potting mix or potting mix with a thick layer of sand on top. The second method is floating. Seeds/seedlings can be planted in either a good mix of about 3 parts sterile potting soil (commercial), 2 parts coarse sand, 2 parts vermiculite, and 2 parts perlite (Stephen Putman). Jiffy-7 peat pellets can also be used (Kelly Irvin). Seeds can be sown individually in small 3-4" (7-10 cm) or planted in a community style with 6 seeds per pot. Community style pots are useful when there is little space but there is always more root disturbance when transplanting.
To sow the seeds directly, lay the seeds flat and cover the them with about 1/8-1/4" (0.5-1 cm) of the potting mix. Place the pots into a tray of water and allow the medium to soak thoroughly. Place the pots on a west facing windowsill and bottom water once a week. Germination takes 2-4 weeks with about 80-100% germination rate. Survival of seedlings at 6 months was about 90% (Stephen Putman). The wet sand method is employed by some gardeners with good success. Fill a pot to about 1" (3 cm) to the top with a well drained mix. Fill the pot almost to the top with sand, wetting the sand as necessary. Make a slit in the sand and insert seeds into the slit sideways, firming the sand around the seeds. Insert the pot in a plastic bag and pit it under lights. Remove the plastic bag when the leaves are about 4-6" (10-14 cm) tall. Transplant the seedlings when the leaves are about 10-12" (25-30 cm) long (John Harris).
The floating method is also popular among growers of Hippeastrum and other flat seeded amaryllids. This is done by placing good seeds into a container of clean water and carefully observe for signs of germination or seeds which appear to have fungus growth on them. Those are seeds which have lost their viability; good seeds should not get infected with water-molds. Some seeds may sink to the bottom during this period. This should not affect their germination. Once the radicle had pushed out of the seeds, carefully lift them with a pair of forceps and plant in a well drained mix (Nhu Nguyen).
There are two groups of hippeastrums functionally classified as evergreen and deciduous. Deciduous species must be allowed to go into a dry winter dormancy. Growers have noted that these species may refuse to flower or the bulbs may even rot as in H. petiolatum. At the end of autumn, deciduous species should be allowed to dry out and go into dormancy. Water evergreen species sparingly during the colder part of the year. Resume watering all species regularly at the beginning of spring. Hippeastrums tend to like being fertilized, especially during active growth (Sahuc 1997 - Herbertia pg. 72-80).
Hippeastrum is vulnerable to fungal infections such as "red blotch" caused by Stagonospora curtisii. They are also the victims of mosaic viruses, which are very easily transmitted and spread. They can also succumb to spider mites and bulb scales. Some species and hybrids can persist with a light freeze where they die down and come back when temperatures are warm enough.
For more photos and information about the species select the appropriate wiki page:
or click on the name in the table below:
For more photos and information about the hybrids select the appropriate wiki page:
or click on the name in the table below: