ORCHID SPECIES CULTURE
Charles and Margaret Baker

Angraecum cultriforme Summerhayes

AKA: N/A. 

ORIGIN/HABITAT: Eastern Africa. Plants are know from as far south as Natal
in South Africa, Malawi, Mozambique, Zimbabwe, Zambia, Tanzania, and
Kenya. This orchid is found in moist evergreen forest and in coastal dune
forest. It is widespread in the warmer coastal areas throughout its range;
but plants also are found on some of the forested mountains in Kenya,
southern Tanzania, and Zimbabwe, with collections reported from as high as
7200 ft. (2200 m). Plants frequently grow near rivers, often near the
ground on the trunks of trees as well as on branches and small twigs. 

CLIMATE: Station #68590, Durban, South Africa, Lat. 29.8S, Long. 31.1E, at
20 ft. (6 m). Temperatures are calculated for an elevation of 500 ft. (150
m), resulting in probable extremes of 105F (41C) and 37F (3C). 

N/HEMISPHERE    JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
F AVG MAX        70   70   71   73   75   77   79   79   78   76   73   71
F AVG MIN        50   53   57   60   63   65   67   67   66   62   55   51
DIURNAL RANGE    20   17   14   13   12   12   12   12   12   14   18   20
RAIN/INCHES     1.1  1.5  2.8  4.3  4.8  4.7  4.3  4.8  5.1  3.0  2.0  1.3
HUMIDITY/%       66   72   73   74   75   74   75   76   77   75   69   63
BLOOM SEASON      *         *         *         *    *    *         *
DAYS CLR @  8AM  20   15   12    9    8    7    8   11   13   16   18   23
DAYS CLR @  2PM  22   17   13    9    8    7   11   11   14   15   18   24
RAIN/MM          28   38   71  109  122  119  109  122  130   76   51   33
C AVG MAX      21.1 21.1 21.7 22.8 23.9 25.2 26.2 26.1 25.6 24.4 22.8 21.7
C AVG MIN      10.0 11.9 14.1 15.8 17.5 18.6 19.7 19.7 19.1 16.9 13.0 10.8
DIURNAL RANGE  11.1  9.2  7.6  7.0  6.4  6.6  6.5  6.4  6.5  7.5  9.8 10.9
S/HEMISPHERE    JUL  AUG  SEP  OCT  NOV  DEC  JAN  FEB  MAR  APR  MAY  JUN

Cultural Recommendations: 

LIGHT: 1800-2500 fc. Initially 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 77-79F (25-26C), and nights average
65-67F (19-20C), with a diurnal range of 12F (6-7C). 

HUMIDITY: Near 75% most of the year, dropping to 65-70% for 3-4 months in
late autumn and early winter

WATER: Rainfall is moderate to heavy from spring into autumn. Amounts then
decrease and remain somewhat low during a relatively dry season that lasts
3-4 months from late autumn through winter. Cultivated plants should be
watered heavily when actively growing; but their roots must dry rapidly
after watering, and conditions around the roots should never become stale
or soggy. Water should be gradually reduced 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 70-71F (21-22C), and nights average
50-53F (10-12C), with a diurnal range of 17-20F (9-11C). Rainfall is
somewhat lower in winter, but conditions are not extremely dry for long
periods. Even though rainfall is low during the dry season, additional
moisture is available from heavy dew, so plants usually receive at least
some moisture on a fairly regular basis. Cultivated plants need less water
in winter, but mounted plants should never go without water for very long
and potted plants should never dry out completely. Fertilizer should be
reduced or eliminated until heavier watering is resumed in spring. 

GROWING MEDIA: Plants may be mounted tightly to a tree-fern or cork slab.
If mounted, however, humidity must be high and plants need at least daily
watering in summer. Several waterings a day may be necessary for mounted
plants during extremely hot, dry weather. Plants also may be grown in
well-drained pots or baskets, but because of the heavy water requirements,
the medium should be open and fast-draining. Roots need dry rapidly after
watering, so the medium should never be become stale or soggy. Repotting
or dividing should be done only when new root growth is just starting.
This allows the plant to become established in the shortest possible time
with the least amount of stress. 

MISCELLANEOUS NOTES: The bloom season shown in the climate table is based
on cultivation records. In South Africa, plants bloom from spring into
autumn; but in Zimbabwe, they bloom in summer and early autumn. 

Plant and Flower Information:

PLANT SIZE AND TYPE: A 3-11 in. (8-28 cm) monopodial epiphyte.

PSEUDOBULB: None. The elongated stem is straight or curved and somewhat
2-edged. It is green when young but turns gray with age. At its base, the
stem is often pendulous from the supporting trunk but then curves at right
angles with all the leaves twisted to face one side. Numerous fleshy,
gray-green roots, which are about 0.1 in. (0.15 cm) in diameter. are
produced along the stem.

LEAVES: 0.8-2.4 in. (2-6 cm) long by 0.2-0.3 in. (0.5-0.8 cm) wide.
Numerous leaves are spaced about 0.3 in. (0.8-0.9 cm) apart in two rows
along the stem. They are strap- to sickle-shaped, yellowish green to
pinkish green, and sometimes marked with darker dots. Leaves have 2
sharply pointed, very unequal lobes at the apex. 

INFLORESCENCE: 1.2-1.6 in. (3-4 cm) long. An inflorescence arises from a
node opposite a leaf, usually below the newest roots on the stem. The
flower spike should not be removed when flowering is completed because as
many as 4 bloomings may occur in subsequent seasons. 

FLOWERS: 1. A single, sweetly scented blossom is produced on each
inflorescence, but several inflorescences may each produce flowers at the
same time. The small pink or greenish brown to apple-green flowers are 0.6
in. (1.6 cm) across. Blossoms carry the lip uppermost (non-resupinate) and
have a slightly inflated spur up to 1 in. (2.5 cm) long. The
linear-lanceolate sepals are up to 0.7 in. (1.8 cm) long and taper
gradually to long, sharply pointed tips. The dorsal sepal is straight and
erect, but the normally straight, obliquely held lateral sepals are
sometimes sickle-shaped and curve so that their tips are crossed behind
the lip. Petals are narrow, horizontal, linear-lanceolate, up to 0.6 in.
1.4 cm) long, and taper gradually to long, sharp points. They spread
widely to each side at the base but curve forward along their length so
that their tips often point almost straight forward. The very concave,
ovate-lanceolate lip, which is 0.3-0.5 in. (0.8-1.2 cm) long by 0.2 in.
(0.4-0.6 cm) wide, has a long, tapering, sharply pointed tip and a spur
that may be straight or slightly curved. The column is 0.1 in. (0.2 cm)
long. 

HYBRIDIZING NOTES: N/A. 

REFERENCES: 

Ball, J. 1978. Southern African epiphytic orchids. Conservation Press
Ltd., Johannesburg. 

Hamilton, R. 1988. When does it flower? 2nd ed. Robert M. Hamilton, 9211
Beckwith Road, Richmond, B. C., Canada V6X 1V7.

la Croix, I. F., E. la Croix, T. la Croix, J. A. Hutson, N.
Johnston-Stewart. 1983. Malawi orchids vol. 1 -- epiphytic orchids.
National Fauna Preservation Society in Cooperation with the Southern
Africa Regional Tourism Council. 

Stewart, J. and B. Campbell. 1996. Orchids of Kenya. Timber Press,
Portland, OR.

Stewart, J., with H. Linder, E. Schlepe, and A. Hall. 1982. Wild Orchids
of Southern Africa. Macmillan South Africa, Ltd., Johannesburg. 

PHOTOS/DRAWINGS: 

Stewart, J. and B. Campbell. 1996. Orchids of Kenya. Timber Press,
Portland, OR.

Stewart, J., with H. Linder, E. Schlepe, and A. Hall. 1982. Wild Orchids
of Southern Africa. Macmillan South Africa, Ltd., Johannesburg. 


Copyright 1998, Charles O. Baker and Margaret L. Baker
Sheet version 24841864

.........................................................................
Please remember that this sheet is for your use only, and though it was
provided free of charge, it may not be reproduced or retransmitted in
any way without permission.
.........................................................................

__________________________________________________________________________
 "Orchid Species Culture" Charles & Margaret Baker, Portland, Oregon USA

    Orchid Culture & Pollination site    http://www.orchidculture.com
                     
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    "Orchid Species Culture Vol. 1 - Pescatorea, Phaius, Phalaenopsis,
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