ORCHID SPECIES CULTURE
Charles and Margaret Baker

Aerangis punctata J. Stewart

AKA: N/A. 

ORIGIN/HABITAT: Madagascar. This recently described epiphytic orchid
(1986) is found in center of the island at about 4600 ft. (1400 m). 

CLIMATE: Station #67109, Arivonimano, Malagasy (Madagascar), Lat. 19.0S,
Long. 47.2E, at 4757 ft. (1450 m). Temperatures are calculated for an
elevation of 4600 ft. (1400 m), resulting in probable extremes of 91F
(33C) and 31F (-1C). 

N/HEMISPHERE    JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
F AVG MAX        69   72   75   79   80   80   80   79   78   78   74   71
F AVG MIN        47   47   49   53   57   59   60   59   60   56   52   48
DIURNAL RANGE    22   25   26   26   23   21   20   20   18   22   22   23
RAIN/INCHES     0.2  0.5  0.2  2.5  5.1  8.3 12.8  8.2  8.6  1.4  0.7  0.4
HUMIDITY/%       68   67   62   64   68   70   73   75   73   73   73   69
BLOOM SEASON                                         *
DAYS CLR @  3AM   3   10    5   10    5    3    4    3    1    8   11    5
DAYS CLR @  3PM   2    6    3    7    2    1    0    1    0    3    6    4
RAIN/MM           5   13    5   64  130  211  325  208  218   36   18   10
C AVG MAX      20.6 22.2 23.9 26.1 26.7 26.8 26.7 26.1 25.6 25.6 23.3 21.7
C AVG MIN       8.3  8.1  9.2 11.4 13.6 14.7 15.3 14.7 15.3 13.1 10.8  8.6
DIURNAL RANGE  12.3 14.1 14.7 14.7 13.1 12.1 11.4 11.4 10.3 12.5 12.5 13.1
S/HEMISPHERE    JUL  AUG  SEP  OCT  NOV  DEC  JAN  FEB  MAR  APR  MAY  JUN

Cultural Recommendations: 

LIGHT: 1200-2000 fc. Plants need filtered or diffused light and should
never be exposed to direct midday sun. Strong air movement should be
provided at all times. 

TEMPERATURES: Summer days average 79-80F (26-27C), and nights average
59-60F (15C), with a diurnal range of 20-21F (11-12C). 

HUMIDITY: 70-75% in summer and autumn, dropping to 60-65% for about 3
months in late winter and early spring. 

WATER: Rainfall is moderate to heavy from late spring to early autumn.
Averages then drop rather abruptly in midautumn at the beginning of the
dry season, that lasts about 5 months until late winter or early spring.
Cultivated plants should be watered heavily while actively growing, but
drainage must be excellent. Water should be reduced in autumn after new
growths mature. 

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 prefer to use a high-nitrogen fertilizer
from spring to midsummer, then switch to a high-phosphate formula in late
summer and autumn.

REST PERIOD: Winter days average 69-72F (21-22C), and nights average
47-48F (8-9C), with a diurnal range of 22-25F (12-14C). Rainfall in the
habitat is low from autumn to early spring. Humidity remains relatively
high throughout the year, however, so considerable additional moisture is
available from heavy dew and late-night mist. Cultivated plants need much
less water in winter, but plants should not be completely without water
for long periods. Occasional early-morning mistings between infrequent
light waterings should be adequate in most growing areas. Water should be
increased somewhat if leaves shrivel or show signs of stress. Fertilizer
should be eliminated until new growth starts and heavier watering is
resumed in spring. 

GROWING MEDIA: Conditions around the roots should be open and well aerated
and should never be stale or soggy. 
As with most Aerangis species, Aerangis punctata probably grows better 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 require several
waterings a day. If leaves start to shrivel or wrinkle or show other signs
of stress, a plant usually will recover and grow well if soaked in water
for about 20 minutes at least 3 times a week. Many growers find it
difficult to keep mounted plants moist enough, so plants often are grown
in small, 3-5 in. (8-13 cm) hanging pots or baskets using a very coarse,
open, fast draining medium to anchor the plant but allow roots to wander
outside the container. Plants should be repotted if the medium starts to
break down. Repotting done just as new roots start to grow enables the
plant to become reestablished in the shortest possible time. 

MISCELLANEOUS NOTES: The bloom season shown in the climate table is based
on the original collection report. Joyce Stewart (1986) reported that
these plants grow best when conditions are cool, well-shaded, and humid
with the minimum night temperature near 50F (10C). 

Plant and Flower Information:

PLANT SIZE AND TYPE: A very small, 1-2 in. (2.5-5.0 cm) monopodial
epiphyte.

PSEUDOBULB/STEM: 0.4-0.8 in. (1-2 cm) long. The stems have grayish roots
with a conspicuously bumpy, warty surface and bright green tips that are
flattened against the substratum.

LEAVES: 0.8-1.4 in. (2.0-3.5 cm) long by 0.2-0.5 in. (0.5-1.2 cm) wide.
Each growth carries 2-4 elliptic, oblong, or elliptic-oblong leaves which
alternate along the stem. Leaves are dull grayish green densely marked
with minute silver dots. The apex of each leaf is bilobed, and the lobes
end sharply on either side of the midrib with a short sinus between them. 

INFLORESCENCE: 1.4-2.2 in. (3.5-2.5 cm) long, including the slender
pedicellate ovary. The peduncle, which is 0.4-0.8 in. (1-2 cm) long,
emerges from the stem below the leaves. 

FLOWERS: 1, occasionally 2-3. Blossoms are up to 1.6 in. (4 cm) across.
Sepals and petals may be greenish or pale brownish. The narrowly
lanceolate sepals are 0.6-0.8 in. (1.4-2.0 cm) long by 0.1-0.2 in.
(0.3-0.4 cm) wide at the base with sharply pointed tips. The dorsal sepal
is erect, and lateral sepals are obliquely spreading. Somewhat spreading,
the strap-shaped to lanceolate petals are 0.5-0.6 in. (1.2-1.6 cm) long by
0.1 in. (0.2 cm) wide at the base. The egg-shaped lip tapers gradually to
a slender, sharply pointed apex. It is widest at the middle or on the
upper half with a wide entrance to the spur at its base. Overall, the lip
is 0.6-0.9 in. (1.6-2.2 cm) long by 0.3-0.4 in. (0.7-0.9 cm) wide near the
middle. The spur, which is 4-5 in. (10-12 cm) long, is funnel-shaped where
it meets the lip and then narrows abruptly, becoming very slender from
there to the tip. The short and broad column is 0.1 in. (0.3 cm) long and
the anther cap has a small, pointed, beaklike projection. 
Aerangis punctata and Aerangis curnowiana is very similar in many
respects, but Aerangis punctata differs in several ways. First, the roots
are wider, flatter, and always have a bumpy surface. Leaves are
differently shaped at the apex, and their surface is dotted with minute
silver spots which appear to have been punctured with a pin when viewed
through a hand lens. It often produces 2-3 flowers on an inflorescence but
Aerangis curnowiana never produces more than a single blossom. Petals of
Aerangis punctata are shorter and narrower than the sepals, but those of
Aerangis curnowiana are all similar. The lip of Aerangis punctata is
somewhat variable in that it is sometimes widest closer to the apex, but
is always wider than the lip of Aerangis curnowiana. 

HYBRIDIZING NOTES: N/A. 

REFERENCES: 

Stewart, J. 1986. Stars of the islands - A new look at the genus Aerangis
in Madagascar and the Comoro Islands - 4. American Orchid Society Bulletin
55(11):1117-1125. 

PHOTOS/DRAWINGS:

Stewart, J. 1986. Stars of the islands - A new look at the genus Aerangis
in Madagascar and the Comoro Islands - 4. American Orchid Society Bulletin
55(11):1117-1125. (Drawing and color photo)


Copyright 1999, Charles O. Baker and Margaret L. Baker
Sheet version 65801903

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

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