Blue Alliums Worksheet

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An attempt in made in this worksheet to list all known blue-flowered allium species. Only true blue species are included, and the legion of mauve and lavender-pink species are omitted from this page. Assuming there are 800 species of allium, the 17 taxa listed below only comprise 2% of the known species, therefore blue is a rare color within the genus.   If you know of other blue species, or have comments, please write to antennaria@aol.com.

Allium sikkimense    copyright  2000 Mark McDonough

The information presented below has been carefully researched and culled from a variety of authoritative sources, then laid out in easy-to-read charts.  An artificial simplified key has been devised to help sort out the blue alliums using only leaf and flower details, without the need to dig plants up or get out a magnifying lens.  I welcome comments, suggestions, and leads to good photos of blue alliums.   - Mark McDonough

 

|   species data chart synonyms chart  |  other bluish alliums  |  simplified key  |  the "un-blue" allium  |  bibliography  |

 

Species Data Chart - the Blue Alliums
#

Species

Author

Pub. Date

Distribution

 

Height

 

Flower

Color

Reference / Comments / Links
01

aucheri

Boiss. 1846

Turkey, Iran,

S.W.Asia

 

40-70 cm

violet blue to violet pink. In Mathew book color is deep violet blue w/ white center.

Ref: Flora of Turkey, Flora USSR,

A Review of Allium section Allium

Book Photo: A Review of Allium section Allium, Plate 10.

Web Photo (slow to load, poor image)

Habitat: seasonally moist meadows, grassy banks, 1800- 2550 m.

Note: similar to hierochuntinum

02

beesianum

W.W.

Smith

1914

China, SW Sichuan, NW Yunnan

20-50 cm

blue, rarely white

Ref: FRPS (Flora of China)

Blue Gallery

Photo

Habitat: slopes & meadows, 3000 - 4200 m.

Note: allied to sikkimense & yuanum

03

caeruleum

Pallas

1773

W.Siberia

C.Asia, China

25-85 cm

bright blue, darker nerve

Ref: Flora USSR,

Blue Gallery

Photo

Habitat: mountain steppe zones, 1100 - 2300 m. 

Note: spelled coeruleum in Flora of the USSR

04

caesioides

Wend. 1969

Afghanistan, NW Himalaya

11-35 cm

sky blue to purplish violet

Ref: Flora Iranica

Habitat: high mountains, 2700 m

Rare and Endangered status

05

caesium

Schrenk

1844

W.Siberia

C.Asia

15-65 cm

azure to pale blue & darker nerve, greyish blue, rarely

white, flower heads sometimes with bulbils

Ref: Flora USSR, Flora Iranica

Blue Gallery

Photo

Habitat: mountain steppe zones to 2000 m, and arid semi-desert areas.

Note: allied species is litvinovii,

Allium species caesium and caeruleum reportedly hybridize in the wild where their distribution overlaps.

06

cyaneum

Regel

1875

China, Korea (normally thought of as a Chinese species, the relatively new variety below extends the range to Korea)

10-30 cm

pale to deep blue

Ref: Flora of China

Blue Gallery

Drawing

Photo

Habitat: forest margins, slopes, meadows, 2100-5000 m.

Note: a dwarf, late blooming allium, flowering Aug.-Sep. In cultivation, found in many forms.   Distinctive on account of the long exserted stamens and semi-terete thread-like leaves.

07

cyaneum var.

       deltoides

S.O.Yu

et al.

1981

Korea

10-30 cm

blue

Ref: Flora of China (mentioned, but species had not been seen by the author of Flora of China).

08

henryi

C.H.

Wright

1895

China

11-25 cm

blue to purple-blue

Ref: Flora of China

Habitat: sunny slopes, 1300-2300 m.

Note: Late flowering; Sep.-Oct.  This species, along with heteronema and stenodon, are allied to cyaneum. Has exserted stamens, flat leaves, and few-flowered umbel.

09

heteronema

Wang &

Tang

1980

China

25-30 cm

purple blue

Ref: Flora of China

Habitat: slopes, 1600-2300 m.

Note: flowers in August.   This species, along with henryi and stenodon, are allied to cyaneum. Has exserted stamens, flat leaves, umbel is open and few-flowered with long unequal pedicels

10

hierochuntinum

Boiss.

1882

Israel, Jordan,

Syria

12-35 cm

violet blue, note: in Mathew book flower color looks pale rose

Ref: A Review of Allium section Allium

Book Photo: A Review of Allium section Allium, Plate 14.

Habitat: steppe, desert, -200-750 m

Note: resembles scabriflorum

11

litvinovii

Drobov.

1971

Uzbekistan

15-65 cm

darker blue than caesium with distinct violet tinge, to a deeper violet, sometimes white-flowered.

Ref: Flora USSR, Flora of Uzbekistan, published in: Conspectus Florae Asiae Mediae, vol. 2, p. 314.

Note: Fergana Mt. Range, southern Tien-Shan, North Pamir-Alai.

Note: also spelled litwinowii, although it is correctly litvinovii, commemorative for the Russion botanist Litvinov.

12

sannineum

Gomb.

1937

Lebanon, N.

Israel (Mt. Hermon)

5-20 cm

blue-violet

Ref: A Review of Allium section Allium, Allium Species of Mt. Hermon

Line Drawing: Allium Species of Mt. Hermon, p.136, Fig. 4.

Habitat: alpine slopes,1800-2800 m

Note: dwarf, large bloom heads

13

scabriflorum

Boiss.

1844

Turkey

10-30 cm

violet blue w/ green nerve, or deep purp. drying bluish, in Mathew's book, flower color looks pale rose.

Ref: A Review of Allium section Allium, Flora of Turkey

Book Photo: A Review of Allium section Allium, Plate 14.

Habitat: steppe, dry sandy places, sandstone slopes, 700 - 1700 m

Note: resembles hierochuntinum

14

sikkimense

Baker 1874

China, Nepal, Bhutan, India, Sikkim

15-40 cm

bright blue

Ref: Flora of China

Blue Gallery

Photo

Habitat: forest margins, scrub, slopes, meadows, 2400-5000 m.

Note: a low, late blooming allium, flowering Jul.-Sep. Distinctive on account of the dense, knob-like head of rich blue flowers.  Allied to beesianum and yuanum.

15

stenodon

Nakai &

Kitag.

1934

China

20-50 cm

blue to purle-blue

Ref: Flora of China

Habitat: forest margins, slopes, pastures, 1600-3000 m.

Note: late flowering, Jul.-Sep., allied to heteronema, henryi, and cyaneum

16

vuralii

Kit Tan

1987

Turkey

10-30 cm?  height not specified

pale bluish violet

Ref: A Review of Allium section Allium

Habitat: saline flats, about 850 m

Note: close to scabriflorum, separated by differences in stamens

17

yuanum

Wang &

Tang

1937

China

17-55 cm

blue

Ref: Flora of China

Habitat: forest margins, meadows in forests, slopes, 2800-3500 m.

Note: late flowering, Aug.-Sep., very closely allied to sikkimense.

 

 

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Synonyms Chart - the Blue Alliums
#

Synonym Name

Author

Pub.

Date

= Valid Species

Reference / Comments
01

ascalonicum

L.

1753

hierochuntinum

(The confused name "ascalonicum" also refers to A. cepa, the cultivated "shallots")

Ref: A Review of Allium section Allium

 

02

azureum

Ledeb.

1830

caeruleum

Ref: Flora USSR

03

brevipes

Ledeb. 1852

aucheri

Ref: A Review of Allium section Allium
04

caerulescens

Boiss.

1859

aucheri

Ref: A Review of Allium section Allium

05

caeruleum

     var. bulbilliferum

Ledeb.

 

caeruleum

Ref: Flora USSR

Note: Most cultivated material appears to be this variety with small bulbils in the inflorescence.

06

carduchorum

C.Koch 1849

aucheri

Ref: A Review of Allium section Allium
07

coerulescens

Don

1826

caeruleum

Ref: Flora USSR

08

cyaneum

      var. brachystemon

Regel 1887

sikkimense

Ref: Flora of China
09

cyclospathum

Freyn 1901

aucheri

Ref: A Review of Allium section Allium
10

faniae

Stearn 1978

aucheri

Ref: A Review of Allium section Allium

Note: Was new name for A. caerulescens Boiss.

11

hugonianum

Rendle 1906

cyaneum

Ref: Flora of China
12

ledschanense

Conrath

& Freyn

1896

aucheri

Ref: A Review of Allium section Allium
13

lipschitzii (sic)

-na- -na-

= A. litvinovii
(not a true synonym, purely a mixup, see comments on the right)

(-na- indicates "not applicable")

Note:  A plant under the erroneous name "lipschitzii" was offered for sale by bulb specialists in Europe for a year or two. The name is a mistake, and A. lipschitzii was never published. The plants sent out under this misnomer were in fact A. litvinovii.
14

kansuense

Regel

1887

sikkimense

Ref: Flora of China

 

15

plurifoliatum

     var. stenodon

J.M.Xu

1980

stenodon

Ref: Flora of China

 

16

renardii

Regel

1880

caesium

Ref: Flora of China, Flora USSR

 

17

szechuanicum

Wang &

Tang

?

cyaneum

Ref: Flora of China

 

18

tibeticum

Rendle

1906

sikkimense

Ref: Flora of China

 

19

tui

Wang &

Tang

1937

cyaneum

Ref: Flora of China

 

20

urceolatum

Regel

1873

caesium

Ref: Flora of China, Flora USSR

 

21

viviparum

Karelin

& Kirilov

1841

caeruleum

Ref: Flora USSR

 

 

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Other "bluish" species
#

Species

Author

Pub. Date

Distribution

 

Height

 

Fower

Color

Reference / Comments / Links
01

filidens

Regel 1875

Central Asia

 

20-60 cm

white, or very pale bluish green,

Flora USSR: greenish -azure

Flora Iranica:

white with green nerves

Ref: Flora Iranica, Flora USSR,

A Review of Allium section Allium

Book Photo: A Review of Allium section Allium, Plate 16, white-flwd specimen.

Habitat: gravelly slopes, lower mountain zones, 300 - 2400 m.

Synonyms: A. karakense Regel, A. ugami Vved.

Note: similar to turcomanicum

02

ophiophyllum

Vved. 1928

Central Asia, Uzbekistan, SW Pamir-Alai

15-40 cm

pale violet with a darker nerve, lustrous blue after anthesis

Ref: Flora USSR

Habitat: mottled outcrops
Note: flowers April-May

03 balansae, sieheanum, tchihatschewii, wendelboanum, kastambulense, armenum, huber-morathii, and others.

All of these Turkish species are related and have flowers described as deep pinkish-mauve.   I only have experience growing sieheanum, with flowers of a beautiful and unique deep lilac-bluish-pink, the bluish glow most apparent under low light conditions.  However I still qualify these species as "pink flowered" or "purplish flowered" rather than blue.  Click on the links below to view photos with good color rendition.
A. sieheanum Photos (4 images)
A. sieheanum Gallery (3 images)
A. sieheanum Drawing

 

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Artificial Simplified Key to the Blue Alliums - with abbreviated species descriptions

The blue alliums do not represent a true taxonomic "alliance", rather they are a collection of separate species and small "subgroups" that simply share the common attribute of having blue flowers.   The following "artificial simplified key" was put together as an identification aid for plants in cultivation.  The species descriptions are simplified, omitting most of the technical jargon that makes botanical descriptions hard to visualize.  To ease the task of identifying plants, the key was specifically designed to use obvious leaf and flower characteristics only, thus avoiding bulb coat diagnostics (which can change during the season and requires digging up the plant) as well as avoiding minute floral characteristics that require a hand lens. If you have a blue allium in flower, it should be possible to use a full flowering stem and a leaf or two, with which to make an identification.

1a

Leaves hollow (fistulose)  -

leaves round in cross-section (terete), sometimes channeled (canaliculate), to rarely 3-sided (trigonous), leaves sheathing the bottom 1/4 - 1/2 (or more) of the flower stem.

 

2a

Stamen filaments with broadened bases, usually with short tooth (cusp) on each side

 

 

 

 

 

 

 

 

 

 

3a

Leaves 3-sided to channeled, inner stamen filaments toothless or with 2 small teeth below middle.

 

Allium caeruleum - bulbs rounded, with papery gray bulb coats, smooth and nerveless; stem 25-85 cm (typically 45-60 cm), sheathed for 1/3 the height with 2-4 leaves; leaves hollow, 3-sided, channeled, smooth or scabrous (rough) along the margins, 2-4 mm wide, shorter than the stem; spathe persistent; umbel nearly spherical, many-flowered, open, often with a few tiny bulbils; pedicels nearly equal and much longer than the flowers; flowers small, starry, tepals cornflower blue with darker nerve, 4-5 mm long; stamens about as long as the flowers, style exserted.  Flowers June - July. 

This species is commonly available in autumn bulb bins and in bulb catalogs.  It is a tallish, slender looking plant that makes a nice splash of deep blue color in the early summer garden.  Tends to be short-lived, flowering less in subsequent years, needing to be replaced with fresh bulb plantings. Often produces amusing anomalous flowers, with one tepal or stamen transformed into a pedicel and sprouting another flower from within a flower.

3b

Leaves semi-cylindrical, channeled, inner filaments with long lateral cusps as long or longer than filament

  4a

Plants generally small (11-22 cm), anthers pointed (mucronate)

 

Allium caesioides - bulbs rounded, papery gray bulb coats; one to rarely two stems per bulb, stems 11-22 cm (rarely taller to 35 cm) sheathed for 1/3 - 1/2 the height with 2-3 leaves; leaves hollow, 1-2 mm wide; spathe persistent; umbel hemispherical to spherical, dense, many-flowered, pedicels about 1.5 cm long, tepals purple-violet or becoming sky blue, with dark blue midveins, 5-6.5 mm long, stamens about 2/3 as long as tepals. 

According to the type publication, Botaniska Notiser, 1969, Vol.122, pp.29-31, A. caesioides comes closest to A. caesium. But A. caesium has a narrower bell-shaped flower, of a more bluish color, tepals have a thicker consistency, and the stamen filaments are longer, with better developed lateral teeth to the inner filaments.  A. caesioides has less rigid leaves with indistinct longitudinal ribs, pointed anthers, and grows at higher elevations. Grows in the shade of taller plants.

4b

Plants generally taller (30 - 60 cm)

  5a

Flowers azure blue, light blue, grayish blue, or rarely white, tepals 4-6 mm

 

Allium caesium - bulbs rounded, bulb coats slightly leathery, gray, with faint parallel nerves; stem 15-65 cm (usually on the taller range) sheathed for 1/4 - 1/2 the height with 2-3 scabrous (rarely smooth) leaves; leaves hollow, nearly round in cross-section, about equal to stem height; spathe short, persistent; umbel dense, many-flowered, rarely with bulbils, pedicels equal, 2-5 times length of tepals, tepals narroly bell-shaped, azure blue to light blue (rarely white), with dark blue midveins, stamens 3/4x or equal length of tepals, style slightly exserted.  Flowers May - June (July).

This is a beautiful species, and evidently rather variable.  The plants I've grown (see photos) are rather tall at about 24" (60 cm), with large showy heads of pure light sky blue with navy blue midveins.  I believe there are some dwarf, darker blue-flowered forms in cultivation, although I have not grown these.  Allium caesium is sometimes confused with A. cearuleum, and reportedly these species hybridize where their distribution overlaps.  Both are slender upright plants, but A. caesium is easily distinguished once you've seen both.  Allium caesium tends to have denser, more upright, semi-fastigiate shaped flower heads, versus the the open globe-shaped head of caeruleum, and caesium has longer, narrow-campanulate florets versus the smaller, more open, starry florets of caeruleum.

5b

Flowers dark blue with distinct violet tinge, flowers narrower and longer, tepals 6 mm

 

Allium litvinovii - description similar to A. caesium, except stems are slender, the flowers are usually darker with a distinct violet tinge, to a deeper violet, the flowers commonly narrow and longer, narrowly cup-shaped, mostly 6 mm long, with deep violet color midveins, style not exserted.  Per the Flora of the USSR, white-flowered plants are also known, found in "considerable numbers" in the Fergana Range.

2b

Stamen filaments, inner ones with long lateral cusps on each side, as long or longer than stamen filament.

 

 

 

 

 

 

 

 

 

 

 

 

 

6a

Leaves sheathing lower 1/2 or more of the flower stems

  7a

Plants tall (40-70 cm), tepals long, 7-9 mm, flowers openly cone shaped (campanulate-conical)

 

Allium aucheri - bulbs rounded, bulb coats slightly leathery, grayish-brown, splitting lengthwise; stems 40-70 cm sheathed for 1/2 the height with 2-4 leaves, stem smooth and wiry; leaves hollow, 1.5-4 mm wide, smooth; spathe 2 segments, persistent; umbel spherical to shuttlecock-shaped (oblong), dense, many-flowered, pedicels 3-6 mm long; tepals violet blue to deep blue, with darker midvein, 7-9 mm long, openly conical shaped; stamens and style shorter than the tepals.  Flowers June - July.

From high elevations (hardiness) and from seasonally moist mountain meadows, this choice species should prove amenable to cultivation compared to allied species from lower elavation desert locations (hierochuntinum, scabriflorum, and vuralii).  It is said to be distinct from the closely allium A. hierochuntinum because the short leaves of A. aucheri develop in spring rather than the autumn as in other species.  A tall, slender species.

7b

Plants dwarf (5-20 cm), stems flexuous, tepals 4-5 mm, flowers bell-shapped (campanulate)

 

Allium sannineum - bulbs rounded, bulb coats reticulate-fibrous; stems 10-20 cm sheathed for 1/2 - 2/3 the height with 2-3 leaves, stems semi-reclining, veined; leaves hollow, rounded in cross-section, slightly taller than stem, 1-2 mm wide; spathe 2 segments,short, persistent; umbel hemispherical to spherical, pedicels 5 mm long (possibly longer), flowers bell-shaped, blue to blue-violet, 4-5 mm long; stamens, anthers, and style are exserted.  Flowers June - August.

A dwarf, alpine species.  Judging from the excellent drawing in Israel Journal of Botany, Vol. 26, No. 3, 1977, page 136, this is a highly desirable species suitable for the rock garden, if only it were available.

6b

Leaves sheathing lower 1/4 - 1/3 of the flower stems

  8a

Tepals 6-8 mm long, stamens and style included (not exserted)

 

Allium hierochuntinum - bulbs rounded, bulb coats are brown, fibrous reticulated; stem 12-35 cm tall sheathed for 1/4 - 1/3 the height with 2-4 leaves, stem smooth, wiry, slender; leaves hollow, thread-thin, 0.5-1.5 mm wide, round in cross-section, smooth; spathe 2 segments, persistent; umbel spherical, dense, pedicels 4-10 mm long, flowers narrow pinched-bell shaped, violet blue, 6-8 mm long, papillose (dimpled) and scabrid; stamens and style shorter than the tepals.  Flowers March - May.

From arid desert steppe, from low to moderate elevation, this species is likely to be difficult and not hardy in my USDA Zone 5 garden.   However, seed of this small, slender, upright species is available from Monocot Nursery, England.  Probably best for a bulb frame or alpine house. Very closely allied to A. scrabiflorum.

8b

Tepals 4-5 mm long, stamens and style equal to tepals or exserted

  9a

Filaments exserted, leaves 1-1.5 mm & shorter to rarely = stems, anthers purple or yellow

 

Allium scabriflorum -  bulbs rounded, bulb coats golden brown, fibrous reticulated, forming clumps; stem 10-30 cm tall sheathed for 1/4 - 1/3 the height with 2-3 leaves, stem smooth, slim, and wiry; leaves hollow, roundish in cross-section and shallowly channeled, shorter to equally stem, thread-thin, 1-1.5 mm wide, smooth or slightly scabrid; spathe 1-2 (or more) segments, persistent; umbel oblong to spherical, dense, pedicels 3-10 mm long, flowers narrow pinch-bell shaped, violet blue with green midvein or deep purple fading bluish (rarely whitish with green midvein), 4-5 mm long, papillose and scabrid; stamens and anthers exserted, style shorter than tepals to slightly exserted, anthers purple to occasionally yellow. Flowers June - July.

Very similar to A. hierochuntinum, but has smaller flowers and exserted stamens.

9b

Filaments ~ equal tepals, leaves 1.5-2 mm, as long or longer than stems, anthers white

 

Allium vuralii -  bulbs rounded, fibrous reticulated bulb coats; stem to 30 cm tall sheathed 1/4 - 1/3 the height with 2 leaves; leaves hollow, thread-thin, 1.5-2 mm wide, as tall or taller than the stems; spathe 2 segment; umbel spherical, dense, many flowered, pedicels about 1 cm long, flowers narrow urn-shaped, 5 mm long, pale bluish violet with green midvein, outer tepals papillose on the midvein; stamen filaments slightly shorter than to slightly longer than the tepals, anthers creamy-white.   Flowers July.

Known only from the "type collection", thus somewhat obscure. 

1b Leaves solid

leaves typically flat, in 1 species roundish in cross section (semiterete) but not hollow, sometimes channeled, or with a keel on the underside, leaves basal in all but 1 species.

 

10a

Leaves basal (not sheathing the flower stems, or only sheathing lower-most base of stem)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

11a

Leaves semi-cylindical in cross-section (semiterete)

 

Allium cyaneum - bulbs appear as narrow, thickened stem-bases, cylindrical, 0.2-0.6 cm thick, bulb coats dark brown, clustered closely together, attached to rhizome; stems 10-30 cm (rarely to 45 cm); leaves 2-4, basal, solid, roundish in cross-section to channeled, thread-like, 1.5-2.5 mm; spathe 1-2 segments, early shedding; umbel irregularly semi-hemispherical, few to moderate flowered, pedicels 1-2 times as long as tepals, flowers deep cobalt blue to light blue or violet blue, openly bell-shaped, starry, tepals 4-6.5 mm long x 2-3 mm wide, stamens long exserted to 2x length of tepals, style exserted.  Flowers August - October.

This species is highly variable, with numerous forms in cultivation.  It's small size, neat cump-forming habit, little fountains of thready bright green foliage, and late flowering, make this a valuable addition to the rock garden.  Normally seen are upright forms that reach 20-30 cm, occasionally they are much smaller plants with a spreading growth habit.  The small starry flowers with long exserted stamens make this species unmistakable.

11b

Leaves flat, sometimes with an underside rib (keel)

  12a

Stamens included (not exserted)

  13a

Flowers large, 11-17 mm, margin of tepals are smooth

 

Allium beesianum - bulbs appear as narrow, thickened stem-bases, cylindrical, 0.5-1.0 cm thick, bulb coats brown, somewhat reticulated at the base, clustered closely together, attached to rhizome; stems 30-50 cm (rarely only 20 cm); leaves 2-4, mostly basal or sheathing the lowermost part of stem, flat, 3-8 mm wide, linear, shorter than stems; spathe 1 segment, early shedding; umbels relatively few-flowered, medium dense, tending to droop to one side or laxly hemispherical, pedicels 1x length of tepals or slightly longer, flowers openly bell-shaped, pure blue, tepals large at 11-14 mm long (rarely up to 17 mm long) x 3.5-5 mm wide; stamens about 4/5 length of tepals.  Flowers August - September.

This is one of the most beautiful and desirable blue alliums, with showy clusters of large true blue flowers.  Does not like hot, dry, sunny locations, and must have an open, well lit location with adequate moisture.  Can be found in cultivation, even though often misnamed.  A white-flowered form is grown in England.

13b

Flowers smaller, 6-10 mm, at least the margin of inner tepals are minutely toothed

 

14a     Inner tepals toothed, ends of tepals rounded, spathe deciduous, leaves flat

Allium sikkimense - bulbs appear as narrow, thickened stem-bases, cylindrical, 0.3-0.5 cm thick, bulb coats dark brown, fibrous and somewhat reticulated at the base, clustered closely together, attached to rhizome; stems 15-40 cm (rarely only 5 cm); leaves 3-4, basal, flat, 2-5 mm wide, thickish, shorter than stem; spathe 1 segment, early shedding; umbel hemispherical, dense, medium-flowered, pedicels short, less than or equal to tepals, flowers bright blue, narrowly bell-shaped or bottle-shaped, barely opening, tepals 6-10 mm long x 3-4.5 mm wide, bluntly rounded at ends, inner tepals irregularly toothed (minutely toothed), stamens only 1/2 - 2/3 length of tepals.   Flowers July - September.

Another excellent blue-flowered allium available in cultivation.  It is often confused with A. beesianum, however A. sikkimense is typically a much smaller plant only 15-20 cm tall, with smaller, narrower, thicker foliage, and tight umbels of nearly closed bottle-shaped flowers.  Also appreciates a cool, moist position in loose, enriched soil, accepting half shade to full sun.

14b     Inner & outer tepals toothed (rarely only inner tepals), ends of tepals pointed, spathe persistent, leaves flat with keeled underside.

Allium yuanum - bulbs solitary or clustered, appearing as thickened stem bases, cylindrical, 0.2-0.4 cm thick, attached to a rhizome, bulb coats brown, somewhat reticulated; stems 17-55 cm; leaves 2-3, narrow, 1.5-3 mm wide, strongly keeled on underside, slightly shorter to slighter taller than stems, basal to slightly sheating stem at base; spathe 1-3 segments, persistent; umbel hemispherical, dense, many-flowered, pedicels about equal to tepals, tepals blue, irregularly toothed on all 6 tepals (rarely just on the 3 inner tepals), sharply pointed at the ends; stamens 1/2 length of tepals.   Flowers August - September.

Very similar to A. sikkimense, but differs markedly by the characteristics noted in the key. Probably not in cultivation.

12b

Stamens exserted

  15a

Pedicels very unequal, 2-4 times length of tepals

 

Allium heteronema - bulbs appear as narrow, thickened stem-bases, cylindrical, 0.8-1.0 cm thick, attached to rhizome, bulb coats dark brown, strongly reticulated and somewhat shaggy; stems 25-30 cm, rounded and angled in cross-section; leaves 2-3, flat, 3-7 mm wide, widest at middle and slowly tapering to a point, midvein evident, leaves more or less equal to stem, basal and sheathing base of stem; spathe 1 segment, persistent; umbel open and few-flowered, pedicels very unequal, 2-4 x length of tepals, ascending with upright flowers in a flat-topped cluster, tepals narrowly bell-shaped, purple-blue, 7mm long x 2-3 mm wide; stamens slightly longer than tepals (exserted), style exserted.  Flowers August.

15b

Pedicels nearly equal, 1-2 times length of tepals

 

Allium henryi - bulbs appear as narrow, thickened leaf bases, cylindrical, 0.4-1.2 cm thick, bulb coats dark brown, strongly reticulated, persistent and shaggy; stems 11-25 cm, finely angled in cross-section; leaves many, flat, 2-5 mm wide, widest at middle and slowly tapering to a point, midvein evident, leaves taller than stem, basal to barely sheathing base of stem; spathe 1 segment, persistent; umbel few-flowered, upright, pedicels sub-equal, 1.5-2 x length of tepals, flowers held upright in a domed cluster, tepals openly bell-shaped, purple-blue to blue, 5.5-7 mm long x 3 mm wide; stamens slightly exserted to 1.5 x length of tepals, style exserted.  Flowers September - October.

10b

Leaves sheathing lower 1/2 of flower stem

 

Allium stenodon - bulbs appear as narrow, thickened stem-bases, cylindrical, 0.3-0.8 cm thick, attached to rhizome, bulb coats blackish brown, fibrous, sometimes slightly reticulated; stems 20-50 cm sheathed for 1/2 the height with 2-4 leaves; leaves linear, flat, 2-3 mm wide, shorter to equalling stem; spathe 1 segment, persistent; umbel hemispherical to nearly spherical, densely many-flowered, pedicels 1-1.5 x legth of tepals, flowers openly bell-shaped, blue to purple-blue, tepals 4-5 mm long x 2-3 mm wide; stamens well exserted, 1.5-2 x length of tepals, style exserted.  Flowers July - September.

 

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True Identity of the Un-Blue Allium - the so-called A. tanguticum 'Blue Skies'

Widely distributed in cultivation, are plants misnamed Allium tanguticum, A. tanguticum 'Blue Skies', and A. tanguticum 'Summer Beauty'.    None of these plants are true A. tanguticum.   The true species is a "bulbous" onion (versus a rhizomatous one) from China, a slender growing plant with thread-thin foliage and knob-like heads of purplish-red flowers (vaguely similar to A. rotundum).  As far as I'm aware, Allium tanguticum is not in cultivation.

The imposter, sold by Zimmerman & McClure and other sources, is actually the common European Allium senescens ssp. montanum.  The imposter has much wider, flat, strap-shaped leaves that are shiny green, building into large clumps, bulbs attached to iris-like rhizomes (a rhizomatous onion), and tall stems with pallid mauvish blooms; a real stretch to call the flowers blue.

The original misidentification started decades ago from a Massachusetts nursery named Blackthorne Gardens, which is long since defunct.  The misidentification is perpetuated by growers that distribute their plants without any research or validation, and in some cases, wantonly ingore efforts to correct the problem.  The two cultivars 'Blue Skies' and 'Summer Beauty' are actually rather inferior to deep pink and rose flowered forms of A. senescens ssp. montanum commonly encountered in cultivation. 

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Bibliography

Hanelt, P., Hammer, K., Knupffer, H. (eds.), 1992. The Genus Allium - Taxonomic Problems and Genetic Resources, Proceedings of an International Symposium held at Gatersleben, Germany, June 11 - 13, 1991, Institute of Genetics and Crop Plant Research, Gatersleben, Germany, pp. 1-359.
Hanelt, Peter, 1990. Key to the Alliums of China, from Flora Reipublicae Popularis Sinicae, translated and annotated by Peter Hanelt, Herbertia 46(2): 140-164.
Kollman, Fania, 1984. Allium treatment in Flora of Turkey and the East Aegean Islands, (ed. Davis, P.H.), Vol. 8: 67-212.
Kollman, Fania, & Schmida, A., 1977. Allium Species of Mt. Hermon, Israel Journal of Botany, Vol.26, No. 3, pp 128-159
Mathew, Brian, 1996. A Review of Allium section Allium, pp. 1-176.
Vvedensky, A.I., 1935. Allium, in Flora of the U.S.S.R., Vol. 4: 87-216
Vvedensky, A.I., 1971. Allium, in Conspectus Florae Asiae Mediae, Vol. 2.
Wendelbo, P., 1969. New Subgenera, Sections, and Species of Allium, Botaniska Notiser, Vol 122, pp. 26-37.
Wendelbo, P., 1971. Alliaceae, in Rechinger, K.H. (ed.), Flora Iranica, No. 76: 2-100.
de Wilde-Duyfjes, B.E.E., 1976. A Revision of the Genus Allium (Liliaceae) in Africa, pp. 1-237.
Wu, Zheng-yi & Peter H. Raven (eds). In Press. Flora of China. Vol. 24 (Flagellariaceae-Marantaceae). Science Press & Missouri Botanical Garden, 2000, Family: Liliaceae, Genus: Allium, by Xu, Jie-Mei, & Kamelin, Rudolf V., available on-line and in PDF format for download at the link above, pp. 1-39.
On-line Flora of China (FOC) - homepage.
Xu, Jie-Mei, 1980. Allium, in Wang Fa-tauan et Tang Tsin (eds.), Flora Reipublicae Popularis Sinicae (Flora of China), Vol. 14: 170-272.

 

 

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This page was last updated on 04/14/01