Accepted Scientific Name: Crassula tetragona L.
Sp. Pl. 283 1753. L.
Origin and Habitat: South-western Cape mountains, radiating north-wards and eastwards. South Africa.
Habitat and ecology: Subsp. tetragona occurs in dry fynbos or renosterbos vegetation.
Synonyms:
See all synonyms of Crassula tetragona
Common Names include:
ENGLISH: Four-angled Crassula, Miniature Pine Tree, Bonsai Pine
ARABIC ( لعربية ): كرسول رباعي الزوايا
CATALAN (Català): Arbre de pi en miniatura
CHINESE (中文): 筒叶菊
FINNISH (Suomi): Ristipaunikko
Description: Crassula tetragonaSN|26848]]SN|26848]] was one of the earliest of the succulents to be cultivated in Europe, described by Linnaeus in 1753. It has woody stems with brown bark, with crossed pairs of leaves. It is found nearly in every succulent garden and so common as to be almost ignored.
Habit: Perennial erect to decumbent arborescent shrubs, repeatedly branched up to 1 m high.
Stem: Erect, terete jointed with brown peeling bark, sometimes rooting and hairless.
Leaves: Decussately opposite, concentrated in four ranks at the upper ends of the branches, deciduous, stalkless, 1-5 cm long, 1-4 mm wide, lanceolate, awled, subulate, pointed, depressed above obscurely four-cornered, subincurved, spreading, glabrous with small distinct leaf sheaths (1-2 mm long). Leaf colour can vary from green to deep, bluish green.
Inflorescence (cyme) Terminal, flat-topped with flowers densely clustered, peduncle 10-150 mm long, with 1-3 pairs of sterile bracts.
Flowers:Small creamy-white nearly urceolate Sepals 1-2 mm, triangular, blunt; petals 1-3 mm, oblanceolate, elliptic, rounded at tip, ridged on back, but without a projection.. Stamens 1-2 mm, anthers brown. Styles less than one third ovary length.
Booming season: Summer.
Chromosome number: 2n=16, 32, 48.
Note: Six subspecies are recognized, the nominate form and subsp. acutifolia, subsp. rudis, subsp. connivens, subsp. lignescens, and subsp. robusta. The subspecies are separated geographically, generally with only one subspecies per geographic area.
Subspecies, varieties, forms and cultivars of plants belonging to the Crassula tetragona group
- Crassula tetragona L.: (subsp. tetragona) is repeatedly branched, with flattish leaves and distinct leaf sheaths (1-2 mm long); the inflorescence is flat-topped with flowers densely clustered. Distribution: S-W Cape mountains.
- Crassula tetragona subs. acutifolia (Lamarck) Toelken: is prostrate and roots at the nodes. Distribution: Rivers-dale to King William's Town.
Crassula tetragona subs. connivens (Schönland) Toelken: has papillose stems, becoming thick, fleshy or woody when old. The inflorescence is round-topped, almost sessile and usually without bracts. Distribution: Little and Great Karoo.
- Crassula tetragona subs. lignescens Toelken: has erect, wiry, woody branches up to 800 mm tall, very short leaf sheaths and 0-1 pairs of sterile bracts on the peduncle. Distribution: Montagu to Grahamstown and also in Namaqualand.
- Crassula tetragona subs. robusta (Toelken) Toelken: has thick fleshy stems, the leaves blunt, upward-curving and longer than 20 mm. Peduncle with 0-1 pairs of sterile bracts. Distribution: Eastern Cape river valleys
- Crassula tetragona subs. rudis (Schönland & Baker f.) Toelken: is sparingly branched, and the inflorescence is irregularly branched. It is very similar to subsp. tetragona, but has fleshy roots. Distribution: Namaqualand.
Bibliography: Major references and further lectures
1) Carl Peter Thunberg “Travels at the Cape of Good Hope, 1772-1775: Based on the English Edition London, 1793-1795” Van Riebeeck Society, The, 1986
2) George Don, Philip Miller “A General System of Gardening and Botany: Founded Upon Miller's Gardener's Dictionary, and Arranged According to the Natural System” Volume 3 C. J. G. and F. Rivington, 1834
3) Edgar Lamb, Brian Lamb “The Illustrated Reference on Cacti & Other Succulents” Volume 5 Blandford Press, 1978
4) Werner Rauh “The Wonderful World of Succulents: Cultivation and Description of Selected Succulent Plants Other Than Cacti” Smithsonian Institution Press, 1984
5) Doreen Court “Succulent Flora of Southern Africa” CRC Press, 01/Jun/2000
6) Stuart Max Walters “The European Garden Flora: Dicotyledons” (Part I) Cambridge University Press, 1989
7) Gordon D. Rowley “The illustrated encyclopedia of succulents” Crown Publishers, 01/Aug/1978
8) Eggli, Urs “Illustrated Handbook of Succulent Plants, Crassulaceae Illustrated Handbook of Succulent Plants.” Springer, Berlin 2002
9) Hermann Jacobsen “Abromeitiella to Euphorbia” Blandford Press, 1960
10) Hermann Jacobsen “A handbook of succulent plants: descriptions, synonyms, and cultural details for succulents other than Cactaceae” Volume 1 Blandford Press, 1960
11) Toelken, H.R. 1997. “A revision of the genus Crassula” in southern Africa. Annals of the Bolus Herbarium 8,1-595.
12) Van Jaarsveld, E., Van Wyk, B-E. & Smith, G. “Succulents of South Africa.” Tafelberg, Cape Town. 2000
13) John Manning “Field Guide to Fynbos” Struik, 2007
14) Vera Higgins “Succulent Plants Illustrated” Blandford Press, 1949
15) Goldblatt, P. and Manning, J.C. “Cape Plants: A conspectus of the Cape Flora of South Africa.” Strelitzia 9. National Botanical Institute, Cape Town. 2000.
16) Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. “Red List of South African Plants.” Strelitzia 25. South African National Biodiversity Institute, Pretoria. 2009
17) Alfred Byrd Graf “Exotica [three] 3: Pictoral Cyclopedia of Exotic Plants” Roehrs, 1963
18) Alfred Byrd Graf “Tropica: Color Cyclopedia of Exotic Plants and Trees” Simon & Schuster, 01/giu/1978
19) Carl von Linné, Johan Elmgren “A System of Vegetables: According to Their Classes, Orders, Genera, Species, with Their Characters and Differences” in Two Volumes, Volume John Jackson, 1783
Cultivation and Propagation: Crassula tetragonaSN|26848]]SN|26848]] is a good beginner plant, fast growing, easy to propagate from cuttings and not prone to pests. It grows under a wide variety of climatic conditions provided it is planted in a well-drained situation given adequate water but not over-watered. They are often grown in small bonsai pots and trimmed to appear as pine trees. C. tetragona plants will branch at the tips and can be used as a low, informal hedge. In the ground for landscaping, they grow up to 120 cm tall.
Growth rate: It is a pretty fast grower.
Soil: Plants grow well in a well-drained mineral soil.
Pots: It needs a relatively shallow pot to accommodate its fibrous roots and provide a very good drainage. It may stay in the same pot for many years.
Watering: It needs moderate water – not too wet nor too dry from autumn to spring with regular water in summer (careful watering required in winter), fairly drought tolerant elsewhere.
Fertilization: Light fertilizer seems to boost its growth whenever additional water is given. Feed it during the growing season with a fertilizer specifically formulated for cactus and succulents (high potash fertilizer with a dilute low nitrogen), including all micro nutrients and trace elements diluted to ½ the strength recommended on the label. It thrive in poor soils and needs a limited supplies of fertilizer to avoid the plant developing excess vegetation, which is easily attacked by fungal diseases.
Special need: Provide very good ventilation. Nearly all problems occur as a result of overwatering and poor ventilation, especially when weather conditions are dull and cool or very humid.
Exposure: It cannot take direct sun in summer but generally needs sun part of the day to bloom. In deep shade it gets pretty weak and leggy and eventually rots and dies. As houseplants, give crassulas up to 6 hours a day of sun.
Pest and diseases: It does not suffer from pests, other than the occasional mealybugs. Protect against frost.
Maintenance: After growing for several years tends to become untidy resulting in thick tops and bare stems at the bottom. Without the pinching and trimming these succulent plants form new branches near the top. To encourage shrubbier growth, pinch off a few leafs at the top or restart it from cuttings.
Uses: These plants are usually used as an ornamental, although they are believed to have been used as a medicinal plant by Thunberg, who wrote: "Crassula tetragonaSN|26848]]SN|26848]], somewhat of an stringent nature, boiled in milk, in the quantity of a handful, is used as a remedy for diarrhoea."
Hardiness: Outdoors in frost free areas, indoors all other zones
Propagation: Seeds/ Stem cuttings. Sow seeds in autumn. Place cuttings in clean river sand, mist every three to four days, roots should appear within 2-3 weeks.
