Pleurothallis urseolata – 365 days of orchids – day 1507


This is one of our largest Pleurothallis speices and a wonderful sight this week. Many pleurothallis species are small plants or even tiny miniatures but some like this species are large dramatic plants with thousands of small flowers on a mature plant. This plant stands 80cm high and is still a relatively young plant.

The flowers have been in bud (like tiny bird’s beaks) for a while and it does take a close inspection to see the fine thread like petals that show flowers have opened. The flowers are not large but the long pendulous flower spikes are very attractive especially since individual leaves can produce up to ten flower spikes.

We are struck with its resemblance to Dendrochilum magnum (below) a species that is not related and comes from the other side of the world. Is this a good case of parallel evolution as both are adapted for a fairly small fly pollinator and present their flowers in a similar way from very different plants.

Pleurothallis urceolata is native to Ecuador where it grows in cloud forests from 1500-2900m altitude and in common with many of the larger leaved pleurothallis it enjoys being kept wet and shaded especially in the summer when overheating can lead to dark blotches on the leaves. This species produces abundant roots which makes culture easier especially in warm weather. To satisfy its culture preference we grow plants hanging low in our cool Americas section where it remains cooler and damper on hot summer days (see flowering in its normal home below)


Moving orchids back from their winter rest

We have moved some of our warm growing species that enjoy a cooler winter (such as Dendroibium aphyllum) back to their warm home in our  Warm Asia section (min 17C). The plants have been hanging in the roof of Cool Americas (min12C) since before Christmas but their native home in Himalayan valleys will now be warming up and we replicate those conditions at school.

As you can see plants have lost all of their leaves but the pendulous pseudobulbs have not shrivelled – we will expect them to flower in about six weeks and until them will keep them on the dry side. (flowering plant below)


Oncidium maculatum – 365 days of orchids – day 1506

Winter seems to have returned outside the greenhouse making the warmth inside especially welcome. A majestic species in flower this week is Oncidium maculatum.

Oncidium maculatum is native to Mexico and Central America where it grows in wet forests from 1000 to 2000m altitude. This habitat suggests it would be happy in either our Warm Americas or our Cool Americas sections and we have grown it in both although we have found that plants do best in Warm Americas where we keep plants wet and in relatively bright light which encourages the large pseudobulbs that flower well.

We grow the species successfully both in pots and in baskets.

The flowers are long lasting and large compared to most Oncidiums making this a really attractive species and one we have used in breeding to make the rather lovely hybrid below which is Oncidium maculatum crossed with Odontoglossum cristatum.

Oncidium maculatum x Odontoglossum cristatum

Odontoglossum cristatum


Adenoncos virens – 365 days of orchids – day 1505

We have had some giant orchids this week but todays orchid has such small green flowers that I almost missed the fact it was in flower!

Adenoncos virens (the green adenoncos) is also the smallest flowered of the three Adenoncos species we grow at Writhlington. (See Adenoncos major and paviflora below)

They may have small flowers but we are very fond of all three miniature species.

Adenoncos virens is found in Malaysia, Java, Borneo and Sumatra in mangroves, lowland and hill forests at elevations of 350 to 1220m and we grow the species warm (min 17C and mounted to show off its lovely form.


Cuitlauziana pulchella / osmoglossum pulchellum / odontoglossum-pulchellum – 365 days of orchids – day 1504

A highlight this weekend is the flowering of this delicate little orchid that has been one of my favourites since I first came across its waxy fragrant flowers in the 1970s.


This exquisite and sweetly scented species species from Mexico and Central America is a cool growing species found in high altitude cool mossy forests from 1200 to 2600m and so we grow plants in our Cool Americas section, shaded and watered throughout the year.

The scent is reminiscent of almonds and is very popular amongst the noses of Orchid Project students. Fortunately the flowers are long lasting, which is unusual for such a scented flower and a plant which is diverting valuable resources to producing fragrance oils, and the species will still be in flower at the end of lockdown when students return. The flower stems are thin and flattened, and over time they become attractively arching and we avoid the widespread habit of fighting the graceful habit by enforcing vertical spikes with canes and ties.

We grow the species amongst our masdevallias (with which it shares its habitat) in our Cool Americas section with a minimum of 12C and lots of water throughout the year. It does particularly well in baskets. I first grew this species as a boy (45 years ago) and it is a species I wouldn’t be without.

The name Cuitlauziana pulchella reflects recent molecular studies into the Oncidium family and this species started life in the Orchid Project as Odontoglossum pulchellum and then Osmoglossum pulchellum before taking on its current name. Either way, ‘pulchellus’ is latin for ‘pretty’ which is a great choice for this pretty little orchid.