| Tragopogon porrifolius | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Tragopogon |
| Species: | T. porrifolius |
| Binomial name | |
| Tragopogon porrifolius | |
| Synonyms[2] | |
| |
Tragopogon porrifolius is a plant cultivated for its ornamentalflower and edible root. It also grows wild in many places and is one of the most widely known species of the salsify genus,Tragopogon. It is commonly known aspurple orcommon salsify,oyster plant,vegetable oyster,Jerusalem star,[3]Jack go to bed,[4]goatsbeard,[5] or simplysalsify (although these last two names are also applied to other species).
The Latinspecific epithetporrifolius means "with leaves likeleek" (Allium porrum).[6]
The plant grows to around 1.2 m (4 ft) in height.[7] As with otherTragopogon species, its stem is largely unbranched and the leaves are somewhat grasslike. It exudes a milky juice from the stems. The taproots can become 15–30 cm (6–11+3⁄4 in) long and2–5 cm (3⁄4–2 in) thick.[8]
In the UK it flowers from May to September, but in warmer areas such asCalifornia it can be found in bloom from April. The flower head is about 5 cm (2 in) across[9] and each is surrounded by green bracts which are longer than the petals (technically, theligules of the ray flowers). The flowers are like that ofTragopogon pratensis, but are larger and dull purple,3–5 cm (1+1⁄4–2 in) across. The flowers arehermaphroditic andpollination is byinsects.
The fruits are beakedachenes, rod-shaped with light ribs. They have hairs at one end that facilitate wind dispersal.[10] The achenes are 10–17 mm long and 1–3 mm wide without counting the beak, which is up to 55 mm in length.[8] When the fruits are formed fully, the hairs from the fruits give the appearance of a ball of fluff which gives the plant its name "goatsbeard".[5]
Tragopogon porrifolius is a commonbiennial wildflower, native to southeast Europe, Mediterranean Turkey, and north Africa,[8] butintroduced elsewhere, for example, into theBritish Isles (mainly in central and southern England),[11] other parts of northern Europe,North America and southernAfrica, and in Australia. In the United States, it is now found growing wild in almost every state, includingHawaii, except in the extreme south-east.
The root and the youngshoots ofT. porrifolius can be eaten (after being boiled).[12] The freshly grown leaves can be eaten cooked or raw.[8][5] Historically, the plant was cultivated for that purpose; it is mentioned by classical authors such asPliny the Elder. Cultivation in Europe began in the 16th century inFrance andItaly. In the United Kingdom it was initially grown for its flower and later became a mildly popular vegetable in the 18th century but then declined in popularity. Presently the root is cultivated and eaten most frequently in France, Germany, Italy andRussia. However, in modern times it has tended to be replaced bySpanish salsify (Scorzonera hispanica) as a cultivated crop.
Cultivated varieties include 'White French', 'Gian French',[4] 'Mammoth Sandwich Island',[13][14] 'Improved Mammoth Sandwich Island', 'Blauetikett',[4] and 'Lüthy';[4] they are generally characterised by larger or better-shaped roots. To maintain the purity of the cultivar a distance of 500 ft (150 m) has to be met. WhenT. porrifolius is grown for seed, it is harvested in the second season from midsummer to early autumn to select for bolt resistance.[8] The root becomes discoloured and spoils quickly if broken, which can easily happen since it is difficult to remove from the soil without damage.
Salsify is grown similarly to other root vegetables likeparsnip andcarrots and thus requires similar attention.[14][15]Sowing can be done in late summer or early winter[14] to foster an early growth.[13] Planting can also be done in early spring about 100 days before the first frosts in a well prepared soil, preferably aloam orsilt-loam.[15] It should be done at the depth of 1.3 to 2 cm. Spacing between rows should be around 45 to 60 cm and the seeds should be separated by 3 cm approximately. This represent 12 g of seeds per 10 m of row for the cultivar 'Mammoth Sandwich Island'. A thinning to 5 cm between the plants is needed when the seedlings reach 5 cm.[14]T. porrifolius needs deep and loose soils which are not too dry for a good development of the taproot. Stony or waterlogged soils have negative effects on yields and hamper harvesting. Other root crops, legumes and cereals have been mentioned as possible preculture.T. porrifolius is a moderate feeder, therefore the application of fresh manure does not benefit yields. During the main growing period a good water supply prevents potential branching of the taproot.[16]
There are no specific requirements known for the cultivation ofT. porrifolius, but they have been successfully cultivated in temperate climate zones.[10] The seedlings need a temperature of 8–16 °C to germinate and the plant will freeze between −1.1 and −1.6 °C.T. porrifolius can cope with low temperatures and is not injured by light freezing.[16][17]
The seeds need 8–10 days of germination time.T. porrifolius is a biennial plant. In the first year only the vegetative parts of the plant are developed. In autumn, the energy is stored in the root system, which is depending on the variety more or less branched. In the second season the generative purple flowers evolve.[16] They bloom from early to mid summer.[10]
The taproots are usually harvested from late autumn onwards (later than October in the Northern Hemisphere) and during winter. Harvesting after a frost is favoured to improve the taste of the root. After flowering, the taproot becomes stringy and inedible.[16] The taproots can be stored in traditionalclamps although refrigerated storage has been recommended at 0 °C and 90–95% relative humidity for 2–4 months.[10][17]
Few pests or diseases affectT. porrifolius. White rust (Albugo tragopogonis) is the most common disease ofT. porrifolius. Closely related wild species (e.g.Tragopogon pratensis), black salsify (Scorzonera hispanica), gerbera (Gerbera) and sunflower (Helianthus annuus) are also found to be hosts of this fungus. At an early stage chlorotic spotting is visible on leaves and stems. These develop during the course of disease into small white blisters.
Occasional problems are reported withrust diseases caused byPuccinia hystericum,Puccinia jackyana andPuccinia scorzonera.[18] Mulching with oats and the use of spring vetch (Vicia sativa) or blue tansy (Phacelia tanacetifolia) as cover crops reduces the number of fungi infecting seedlings and roots. The following fungi have been isolated fromT. porrifolius seedlings and roots:Alternaria alternata,Fusarium culmorum,Fusarium oxysporum,Penicillium spp.,Rhizoctonia solani andSclerotinia sclerotiorum.[19]
When the rows are planted too close together, powdery mildew (Erysiphe cichoriacearum) can affect the plants.[17]
When the roots are left in the ground over winter, mice and voles may nibble them.[17]
| Nutritional value per 100 g (3.5 oz) | |||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Energy | 343 kJ (82 kcal) | ||||||||||||||||||||||||||||||||||||||||||||||
18.6 g | |||||||||||||||||||||||||||||||||||||||||||||||
| Dietary fiber | 3.3 g | ||||||||||||||||||||||||||||||||||||||||||||||
0.2 g | |||||||||||||||||||||||||||||||||||||||||||||||
3.3 g | |||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||
| Other constituents | Quantity | ||||||||||||||||||||||||||||||||||||||||||||||
| Water | 77 g | ||||||||||||||||||||||||||||||||||||||||||||||
| †Percentages estimated usingUS recommendations for adults,[20] except for potassium, which is estimated based on expert recommendation fromthe National Academies.[21] | |||||||||||||||||||||||||||||||||||||||||||||||
Alatex derived from the root can be used as achewing gum.[citation needed]
The plant is edible,[22] but the roots and leaves are most palatable when collected before the flower stalk is produced.[23] The root is noted for having a mild taste when uncooked, described as like asparagus oroysters, from which the plant derives its alternative name of oyster plant. The outer layers can be scraped off, with the root dipped in cold water to preserve its colour.[23] If too tough for eating, they can be boiled with a pinch of baking soda and a change of water.[23] Raw young roots can be grated for use in salads, but older roots are better cooked. They can be added to soups, stews or stir-fries. Salsifypurée (alone or including potato) is recommended with fish.[24]
The flowering shoots can be used likeasparagus, either raw or cooked and the flowers can be added to salad, while the sprouted seeds can be used in salads or sandwiches.
Raw salsify is 77% water, 19%carbohydrates, 3%protein and contains negligiblefat. In a 100 gram reference amount, raw salsify supplies 82calories and moderate contents ofriboflavin,vitamin B6,vitamin C,manganese andphosphorus.
Tragopogon porrifolius containspolyphenolphytochemicals which are under preliminary research for their potential biological effects.[25]Tragopogon species are being studied at thebiochemical level for their novelenzyme forms andgenetic polymorphism.[26]
Type Specimens:Tragopogon porrifolius
