Hymenocallis littoralis (PROSEA)
Hymenocallis littoralis (Jacq.) Salisb.
- Protologue: Trans. Hort. Soc. London 1: 338 (1812).
- Family: Amaryllidaceae
- Chromosome number: 2n= 44, 46, 48, 68
- Spider lily (En)
- Philippines: bakong, lirio (Tagalog), ajos-ajos nga maputi (Bisaya)
- Thailand: phlapphlueng teenpet (Bangkok)
- Vietnam: bạch trinh biển.
Origin and geographic distribution
H. littoralis originates from South and Central America, but it is cultivated and naturalized in tropical Africa, Asia and the Pacific islands. In the Malesian region, it is recorded as naturalized in Java, the Philippines and the Bismarck Archipelago.
In the Philippines the bulbs of H. littoralis are used as a vulnerary. However, in Thailand they are considered too toxic to be eaten. In Chinese traditional medicine Hymenocallis leaves are applied externally to swellings and bruises.
The bulbs of Hymenocallis are commonly used in traditional medicine in Central America, most commonly in a decoction taken internally to treat asthma, and as a poultice on boils. Sometimes the flowers are also used in a decoction against cough.
Several Hymenocallis species, including H. littoralis , are commonly cultivated as a garden ornamental in the warmer parts of the world. A cultivar of H. littoralis (“Variegata”“) with leaves striped bright green and edged cream is popular among gardeners.
Several compounds with antitumour and antiviral activities have been isolated from H. littoralis bulbs. Lycorine alkaloids (also known as amaryllidaceae alkaloids) are responsible for these activities, e.g. littoraline, which shows inhibitory activity of HIV reverse transcriptase, and lycorine, haemanthamine, which show potent in-vitro cytotoxicity, also against drug-resistant cell lines. The antiproliferative effects of lycorine and haemanthamine result from their complex formation with RNA. Biosynthetically, these compounds are derived from the amino acids tyrosin and phenylalanin. Pancratistatin, narciclasine and 7-deoxynarciclasine are isocarbostyril-type compounds which have antineoplastic activity against a panel of human tumour cell lines and which are present in several Hymenocallis species including H. littoralis . Pancratistatin has been under development as an anticancer agent. The related compound 7-deoxy-trans-dihydronarciclasine, isolated from H. littoralis and some other Hymenocallis species, inhibited the cytopathicity and/or replication of various viruses.
Lycorine inhibited feeding of desert locusts when sprayed on cabbage leaves in a concentration of 0.05% under laboratory conditions. Antifungal properties have also been recorded for bulb extracts of H. littoralis . Some Hymenocallis species showed marked activity against avian malaria.
A perennial herb up to 80 cm tall, with spherical bulb 7.5-10 cm in diameter. Leaves radical, 2-seriate, simple, lorate to linear, 40-120 cm × 1.5-5(-7) cm, acute at apex, sessile. Inflorescence a pseudo-umbel with somewhat compressed peduncle up to 60 cm long, with 2 spathes, 6-11-flowered. Flowers bisexual, large, regular, 3-merous, white, fragrant, sessile; tepals 6, equal, united into a long tube 9-17 cm long, segments linear, 7.5-12 cm long, channelled, with an apical cusp; stamens 6, inserted in the perianth throat and connate at base into a false corona 2.5-3 cm long, free part of filaments c. 6 cm long, anthers with orange pollen; ovary inferior, 3-celled, style filiform, slightly exceeding the stamens, stigma small and capitate. Fruit a fleshy capsule, finally rupturing laterally, few-seeded. Seeds large, with thick, spongy, green testa.
Hymenocallis comprises about 50 species and its natural area of distribution is Central and South America. Several species other than H. littoralis are cultivated as an ornamental in the Malesian region, e.g. H. caribea (L.) Herbert, H. narcissiflora (Jacq.) MacBr. and H. speciosa (Salisb.) Salisb., but only H. littoralis has become naturalized.
H. littoralis occurs along the seashore and inland in moist, sandy locations at low altitude. It is cultivated in gardens up to 1500 m altitude.
Management H. littoralis is best grown in a light, well-drained potting mix of equal parts of loam, leaf mould and sand. Propagation is by seed, but more usual by offsets. Methods for large-scale propagation by tissue culture have been developed for H. littoralis . In-vitro production of pancratistatin was also successful in callus cultures, but the concentration was only about 10% of that in bulbs of field-grown plants. Experiments in the United States showed that atmospheric CO2enrichment may increase the concentration of active constituents in the bulbs by 75%.
H. littoralis is widely cultivated and consequently does not seem to be threatened. However, nothing is known about the genetic diversity of cultivated and naturalized plants in South-East Asia, and this may be very low. In Central America several Hymenocallis species are classified as endangered. In Puebla (Mexico) a germplasm collection of ornamental geophytes is maintained, including Hymenocallis .
H. littoralis is an interesting medicinal plant, which deserves more attention in South-East Asia. It is a source of compounds with anticancer and antiviral (including anti-HIV) activities, but the reputed beneficial effects of bulb extracts internally on asthma and cough as well as externally on wounds, swellings, bruises and boils also merit more attention and research.
63, 247, 393, 563, 737, 760.
Other selected sources
62, 120, 346, 646.
Main genus page
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