AFRICAN

ORCHIDS

Aerangis × chirioana Bellone & Chiron, Richardiana 2: 132 (2002).
Description:
Plante épiphyte relativement grande, à tige robuste de 11 cm de longueur et environ 1-1,5 cm de diamètre, portant jusqu'à 15 feuilles distiques, espacées de 10-15 mm l'une de l'autre. Nombreuses racines longues et épaisses, 3-5 mm de diamètre, blanc gris à apex orange, prenant naissance tout le long de la tige mais principalement à sa base. Feuilles vert bouteille, coriaces, la face supérieure brillante, la face inférieure tachetée de petits points noirs clairsemés, sauf à la base où ils sont plus denses, largement obovales à claviformes, falciformes, 10-24 x 5,59,5 cm (les feuilles des jeunes plantes étant plus étroites que les feuilles des plantes plus âgées), carénées dessous, la base engainante, l'apex inégalement bilobé, lobes aigus, le petit parfois obtus, le petit lobe 8-16 mm, le plus grand 20-33 mm, les marges ondulées, surtout la marge extérieure. Inflorescences 1-3, pendantes, 45-80 cm, beaucoup plus longues que les feuilles, produisant jusqu'à 40 fleurs ; les fleurs du milieu de l'inflorescence s'ouvrent d'abord, puis celles de la base, puis les fleurs de la partie apicale, au fur et à mesure que l'inflorescence s'allonge : la floraison peut durer trois ou quatre mois ; pédoncule de 20 cm de longueur environ, couvert de 8-10 bractées amplexicaules, 9 mm de longueur et 10 mm de largeur, arrondies à l'apex, parcheminées, brunes à noires ; fleurs en racème, à peu près régulièrement espacées de 2-3 cm, une (rarement deux) à chaque nœud. Bractées florales de deux types: les inférieures semblables aux bractées du pédoncule, les supérieures foliacées, vertes, coriaces, ovales à subcirculaires, en forme de cuiller, de plus en plus petites en allant vers l'apex, la plus grande environ 20 x 15 mm. Pédicelle-ovaire long d'environ 3 cm. Fleur peu variable d'une plante à l'autre, blanche à peine teintée de saumon très pâle, ne changeant pas de couleur en vieillissant, l'apex des sépales saumon, l'éperon saumon, d'abord verdâtre sur la moitié basale, puis totalement saumon en vieillissant, odorante le jour, à périanthe bien ouvert avec les pétales et le labelle un peu réfléchis, 4 cm de diamètre environ. Sépales oblongs, aigus, les latéraux obliques, 25-30 x 5-7 mm ; pétales ovales, aigus, l'apex un peu courbé vers le bas, similaires au sépale dorsal, environ 26 x 46 mm ; labelle à peine panduré, à marge irrégulière, les marges de l'apex repliées en une sorte de gouttière, dépourvu de cal, 24-30 x 7-10 mm ; éperon légèrement courbé, long et fin, 50-60 x 1,3 mm à la base, s'amincissant régulièrement jusqu'à l'apex, qui est légèrement bifidé; colonne courte et trapue, 4-5 mm de hauteur, 3 mm de largeur dans sa partie la plus large, droite; anthère conique, blanche, un peu translucide ; pollinies 2, fixées à un viscidium subsphérique, orange, par un stipe plat, translucide, en fer de lance.
English translation required.
Habitat:
?

Cultivation:
As given for the genus.
Notes:
Nous tenons à remercier Joyce Stewart et Isobyl La Croix pour le temps qu'elles ont consacré à l'examen du matériel que nous leur avons soumis et pour les avis qu'elles nous ont fournis. Joyce Stewart, notamment, a, la première, suggéré qu'il pouvait s'agir d'un hybride entre Aerangis biloba et A. kotschyana.
Distribution:
SW. Cameroon
References:
Bibliographie Stewart, J., 1979. A revision of the African species of Aerangis (Orchidaceae). Kew Bulletin, vol.34(2) :239-319. Summerhayes, V. S., 1968. 199. Orchidaceae, in J. Hutchinson & J. M. Dalziel, Flora of West Tropical Africa, Vol.3, part.1, pp. 180-276. Millbank, Londres. Szlachetko, D. L. & T. S. Olszewski, 2001. Flore du Cameroum, Vol.36: Orchidacées (3). Minrest, Yaoundé; WCSP (2017). 'World Checklist of Selected Plant Families. 10.01-2017; http://apps.kew.org/wcsp/
Images:
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Aerangis luteoalba var. rhodosticta (Kraenzl.) J.Stewart, Kew Bull. 34: 310 (1979).
Homotypic Synonyms:
Angraecum rhodostictum Kraenzl., Notizbl. Königl. Bot. Gart. Berlin 1: 154 (1896).
Angorchis rhodosticta (Kraenzl.) Kuntze, Deutsche Bot. Monatsschr. 21: 173 (1903).
Aerangis rhodosticta (Kraenzl.) Schltr., Beih. Bot. Centralbl. 36(2): 119 (1918).
Heterotypic Synonyms:
Angraecum albidorubrum De Wild., Bull. Jard. Bot. État Bruxelles 5: 180 (1916).
Aerangis albidorubra (De Wild.) Schltr., Beih. Bot. Centralbl. 36(2): 113 (1918).
Angraecum mirabile auct., Gard. Chron., ser. 3, 73: 17 (1923), nom. illeg.
Description:
A small, usually pendulous, monopodial epiphyte that is almost stemless. The short stem is hidden by the basal sheaths of closely set leaves. The roots are often flattened, with thin velamen, are green when wet, and have emerald green tips. Leaves: 6-10. The narrowly strap-shaped leaves are bright green, usually less than 6 in. (15 cm) long, and are succulent and fragile. Inflorescence: 2-3 inflorescences that are usually pendulous, and may reach 15 in. (38 cm) in length, emerge from the lower leaf axils. Flowers: 6-25 on each inflorescence. They are produced in 2 rows on a single plane. The 1-2 in. (2.5-5.0 cm) flowers are long lasting, but are not fragrant. They open very flat, and are well spaced on the inflorescence, which gives the plant a very neat and tidy appearance. Color varies from pure white to ivory white, cream, or pale yellow. The column is bright scarlet or vermilion, which creates a very striking contrast.
Habitat:
The species grows across equatorial Africa from Cameroons and the Congo Republic in the west through the central and western forests of Uganda to Somalia, Ethiopia and Kenya in the east. In Kenya, the plants are usually found at 3000-5000 ft. (910-1520 m) on the southern and southeastern slopes of Mt. Kenya and on the southern slopes of Mt. Elgon. Aerangis rhodosticta grows in warm, moist conditions, almost always in forests along rivers. Plants normally grow in areas well protected from drought, often near waterfalls. They usually grow on twigs and branches of shrubs, but are occasionally found on tree trunks.
Cultivation:
One of the most ornamental miniature orchids, with long-lasting, 4-6 weeks, flowers, it requires a shaded position, high daytime temperatures (24-28 °C), with high daily temperature range, ideal of 10-12 °C, and humidity, 70-90%, during the vegetative period in spring-summer, cooler conditions (4-5 °C less) and dry (around the 60%) in winter during the rest; a good air movement is important. It prefers to stay on a cork raft or on branches, possibly with some sphagnum at the base; it can be cultivated also in pot with medium-sized bark, or other draining material, but the risk of stagnating humidity is bigger with consequent radical rottenness. Rainwater, or water obtained by reverse osmosys or demineralized is to be used for the waterings and the nebulisations. It is quite sensitive to the damage of the roots and therefore a particular care is to be taken in the repotting or in the positioning on bark. The fertilizations, appropriately distributed in way to avoid accumulation of salts, are to be done preferably with balanced water-soluble products, with micro-elements, at half dosage, or less, of what suggested on the package.
Distribution:
WC. & E. Trop. Africa to S. Ethiopia
References:
Beaton, C. 1985. Indoor light culture for Aerangis rhodosticta. American Orchid Society Bulletin, 54(8):963; Bechtel, H., P. Cribb, and E. Launert. 1980. Manual of cultivated orchid species. MIT Press, Cambridge, Mass.; Cavestro, W. 1980. Aerangis rhodosticta (Krzl) Schltr. - An African pygmy. American Orchid Society Bulletin, 49(5):509; Hawkes, A. D. (1965) 1987. Encyclopaedia of cultivated orchids. Faber and Faber, London; Hillerman, F. 1986. Growing Aerangis Orchids. American Orchid Society Bulletin, 55(8):803; Hillerman, F. E., and A. W. Holst. 1986. An introduction to the cultivated Angraecoid orchids of Madagascar; Timber Press, Portland, Ore.;Northen, R. T. 1980. Miniature orchids. Van Nostrand Reinhold, New York; Piers, F. 1968. Orchids of East Africa-Nairobi, Kenya. Verlag von J. Cramer, 3301 Lehre; Stewart, J. 1984. Growing Angraecoid orchids - Part 1 - Introduction. American Orchid Society Bulletin, 53(7):731.;Text from Dr. Giuseppe Mazza and his Contributors; http://www.photomazza.com/?-Copyright-&lang=en; WCSP (2017). 'World Checklist of Selected Plant Families. 19.01-2017; http://apps.kew.org/wcsp/
Images:
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In culture In culture In culture In culture In culture In culture
Aerangis luteoalba var. rhodosticta 01 Aerangis luteoalba var. rhodosticta  02 Aerangis luteoalba var. rhodosticta  03 Aerangis luteoalba var. rhodosticta  04 Aerangis luteoalba var. rhodosticta  05 Aerangis luteoalba var. rhodosticta  06
Photograph Gilles Grunenwald. Image used with kind permission. Photograph Gilles Grunenwald. Image used with kind permission. Photograph Gilles Grunenwald. Image used with kind permission. Photograph Gilles Grunenwald. Image used with kind permission. Photograph Gilles Grunenwald. Image used with kind permission. Photograph Gilles Grunenwald. Image used with kind permission.







 

 

 

Read more of cultivation of Aerangis verdickii (De Wild.) Schltr.
Culture:
Light:
2500-4500 fc. Light should be somewhat filtered or diffused, and plants should not be exposed to direct midday sun. Strong air movement should be provided at all times.
Temperatures:
Summer days average 80-81F (27C), and nights average 59-60F (15-16C), with a diurnal range of 21F (12C). Because of the range in habitat elevation, these plants should adapt to temperatures a few degrees cooler or as much as 12F (7C) warmer than indicated in the preceding climate table.
Humidity:
60-65% in summer and early autumn, dropping to 50-55% from late autumn through the following spring. Averages in the habitat are probably somewhat greater than indicated in the preceding climate table, however.
Water:
Rainfall in the habitat is moderate from late spring into early autumn. Amounts then drop fairly rapidly into a dry season that extends from mid autumn into early spring. Cultivated plants should watered regularly while actively growing, but their roots should be able to dry fairly rapidly after watering. Water should be reduced after new growth has matured in late autumn.
Fertilizer:
1/4-1/2 recommended strength, applied weekly when plants are actively growing. Many growers prefer to use a balanced fertilizer throughout the year; but others use a high-nitrogen fertilizer from spring to midsummer, then switch to one high in phosphates in late summer and autumn.
Rest period:
Winter days average 67-71F (19-22C), and nights average 36-41F (2-5C), with a diurnal range of 30-31F (17C). Growers are reminded that these plants should adapt to temperatures a few degrees cooler or as much as 12F (7C) warmer than indicated in the preceding climate table. Rainfall in the habitat is low for 5-6 months from mid autumn into early spring, but humidity is high enough so that the large range in temperatures results in heavy dew and late-night and early-morning mist during most of the dry season. Water should be greatly reduced for cultivated plants in winter, but they should not be left completely without water for long periods. If humidity is high, occasional early-morning mistings between infrequent light waterings should provide sufficient moisture in most growing areas. Fertilizer should be eliminated until new growth starts and heavier watering is resumed in spring.
Growing media:
As with most Aerangis species, Aerangis verdickii probably is more easily managed and the pendent flower spikes are more easily displayed when plants are mounted on slabs of tree-fern or rough bark. Mounted plants need high humidity, however, and during hot, dry weather they may need several waterings a day. If it is difficult to keep mounted plants moist enough, they may be grown in a shallow pot or basket filled with a very open, fast-draining medium that has excellent drainage, is well aerated, and allows the medium to dry fairly rapidly after watering. Growers generally use coarse fir bark or shredded tree-fern fiber and add varying amounts of chunky perlite and/or chopped sphagnum moss to keep the medium open and retain some moisture in exceptionally dry areas. Including charcoal in the mix also holds the medium open and prevents souring in the pot. Plants should be repotted immediately if the medium starts to break down or whenever the plant outgrows its container. Repotting should be done just as new roots start to grow. This enables the plant to become reestablished in the shortest possible time.
Notes:
la Croix & la Croix (1997) stated, "It grows easily (as perhaps might be expected from its wide altitudinal range) and flowers regularly. Intermediate temperatures seem to suit it, but it needs fairly good light and must be kept dry in winter to avoid stem rot, the greatest risk." Growers report that these plants are in bloom for a long time.
References:
This information is quoted from a Charles and Margaret Baker culture sheet, with permission from Troy Meyers This email address is being protected from spambots. You need JavaScript enabled to view it.. The entire culture sheet can be obtained by subscription from Orchid Species Culture, http://orchidculture.com

 

 

 

 

 

 

Aerangis lacroixiae J.M.H.Shaw, Orchid Rev. 121(1301, Suppl.): 15 (2013).
Homotypic Synonyms:
Angraecum oliganthum Schltr., Ann. Mus. Colon. Marseille, sér. 3, 1: 197 (1913).
Chamaeangis oligantha (Schltr.) Schltr., Beih. Bot. Centralbl. 36(2): 110 (1918).
Microterangis oligantha (Schltr.) Senghas, Orchidee (Hamburg) 36: 22 (1985).
Aerangis oligantha (Schltr.) P.J.Cribb & Carlsward, Phytotaxa 71: 44 (2012), nom. illeg.
Description:
Very small sub acaulis plants 5-6 cm tall, with 4.7 elliptical-lingulate leaves (5-6 x 0.8-1 cm), very shortly contracted basally, widest medially. Inflorescences 10 cm long, with 8-15 loosely arranged flowers, bracts oval, slightly shorter than the pedicel. Sepals oval-oblong, obtuse, 2.5 mm long, the laterals slightly arched. Petals elliptical-obtuse. Labellum oval-lanceolate-acute (2.5 x 1.5 mm, slightly below the center): spur clavate, obtuse, 1.25 mm long, shorter than the pedicel and the labellum. Column short; rostellum subulate; pollina globulous; cauda linear, attenuate apically; viscidium small and rounded. Pedicel 1.5 mm long
Habitat:
Epiphyte of trees front tropical forests; flowering: June.
Cultivation:
As given for the genus.
Distribution:
N. Madagascar
References:
WCSP (2017). 'World Checklist of Selected Plant Families. 19.01-2017; http://apps.kew.org/wcsp/
Images:
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Read more of cultivation of Aerangis ugandensis Summerh.
Culture:
Light:
1200-2000 fc. This species grows well with indoor window sill or artificial light culture. When fluorescent lights are used, growers report success placing plants 6-9 in. (15-23 cm) below the lights.
Temperatures:
Summer days average 72-78F (22-26C), and nights average 53-54F (12C), with a diurnal range of 19-24F (11-13C).
Humidity:
Averages are not available for this location. Records from nearby stations indicate that over the region averages are 70-75% most of the year, dropping to near 65% for a short period in early spring. In late summer, values increase for a short period before falling to 55-60% for 3 months. Conditions may well be more humid in the riverine forests of the habitat than is indicated by the data recorded at weather stations, however.
Water:
The double wet - double dry rainfall pattern depicted in the weather data is common throughout the equatorial regions. The wet seasons occur in spring and autumn, while winter is the primary dry season with a secondary dry season occurring in summer. It is not known whether or not the double rainfall cycle is important to the health or blooming of this species. It does play an important role as the bloom trigger for other plants that originate in areas with the same rainfall pattern, however. Cultivated plants should be kept moist during periods corresponding to the wet seasons. They should be allowed to dry slightly between waterings during the dry seasons, but should never dry out completely or be left dry for extended periods. If the weather is hot, mounted plants should be drenched daily, or soaked (dunked) 3 times a week.
Fertilizer:
A balanced fertilizer, mixed at 1/4-1/2 recommended strength, should be applied weekly during periods of active growth. Many growers use a fertilizer with lower nitrogen and higher phosphate in autumn. If pots are used, the medium should be leached every few weeks to prevent salt buildup, especially when fertilizer is being applied most heavily. Plants should first be watered normally to dissolve any accumulated salts. An hour or so later, the medium is flushed with water equal to about twice the volume of the pot. Year-round leaching is important in areas with heavily mineralized water.
Rest period:
Winter days average 67-70F (19-21C), and nights average 53-54F (12C), with a diurnal range of 14-16F (8-9C). Rainfall is low during a 4-month period in winter and for 2 months in summer. However, high humidity in the stream-side habitat and nightly cooling results in some moisture being available from dew. In cultivation, these conditions may be simulated by early morning mistings, with thorough waterings given every two weeks or so. Plants should be watched carefully for signs of stress while water is reduced, particularly in summer. Water should be increased if such signs appear.
Growing media:
As with most Aerangis species, Aerangis ugandensis probably is more easily managed and the pendent flower spikes are more easily displayed when plants are mounted on slabs of tree-fern or rough bark.. Mounted plants need high humidity, however, and during hot, dry weather they may need several waterings a day. If it is difficult to keep mounted plants moist enough, they may be grown in a shallow pot or basket filled with a very open, fast-draining medium that has excellent drainage, is well aerated, and allows the medium to dry fairly rapidly after watering. Growers generally use coarse fir bark or shredded tree-fern fiber and add varying amounts of chunky perlite and/or chopped sphagnum moss to keep the medium open and retain some moisture in exceptionally dry areas. Including charcoal in the mix also holds the medium open and prevents souring in the pot. Plants should be repotted immediately if the medium starts to break down or whenever the plant outgrows its container. Repotting should be done just as new roots start to grow. This enables the plant to become reestablished in the shortest possible time.
References:
This information is quoted from a Charles and Margaret Baker culture sheet, with permission from Troy Meyers This email address is being protected from spambots. You need JavaScript enabled to view it.. The entire culture sheet can be obtained by subscription from Orchid Species Culture, http://orchidculture.com