Angraecum crassum

Angraecum crassum Thouars is an epiphytic orchid accepted by Kew Plants of the World Online and recorded from northeastern Madagascar [1]. It is a thick-stemmed, thick-leaved species with fleshy flowers, but the supplied evidence for species-specific cultivation is limited and partly conflicting [3][4][5].

Names and Taxonomy

Kew Plants of the World Online accepts Angraecum crassum Thouars and records its first publication as 1809 in Nouv. Bull. Sci. Soc. Philom. Paris, sér. 2, 1: Tabl. Angorkis [1]. Horticultural sources list the name as Angraecum crassum Thouars 1822, and the Spanish Wikipedia entry cites Histoire Particulière des Plantes Orchidées t. 70–71 (1822) [3][4]. The difference may reflect different publication or illustration dates, but the supplied snippets do not resolve it; the accepted name status itself is supported by POWO [1].

POWO lists five synonyms: Aerobion crassum (Thouars) Spreng., Angorkis crassa (Thouars) Kuntze (nom. superfl.), Angorkis crassangis Thouars, Angraecum crassiflorum H.Perrier, and Angraecum sarcodanthum Schltr. [1]. These are alternative names, not separate accepted species in POWO. IOSPE gives the common name Thick-Leafed Angraecum and places the species in section Angraecum [3]; that sectional placement should be checked against a current taxonomic treatment. No varieties or subspecies are documented in the supplied evidence.

How to Identify This Species

POWO describes A. crassum as an epiphytic subshrub [1]. IOSPE describes a medium-sized, hot-growing epiphyte with an erect, thick stem and thick, stiff, linear leaves that are unequally bilobed at the apex [3]. The Spanish Wikipedia summary repeats the thick, erect stem and thick, stiff, linear, unequally bilobed leaves [4]. One secondary database gives a height of 30 cm, but that measurement is not corroborated by the other supplied sources and should be treated as provisional [5].

The most specific flower data come from IOSPE: an inflorescence about 18 cm long, bearing 5 to 12 thick, fleshy flowers about 4 cm across, turning yellow with age [3]. The Spanish Wikipedia entry also reports 5 to 12 flowers, 4 cm wide, thick and fleshy, and yellow [4]. By contrast, NativePlants.info lists white or greenish-white flowers and blooming in every month, which conflicts with the IOSPE and Spanish summaries [5]. Because these snippets disagree, flower color and season should not be treated as fixed diagnostic facts without corroboration. Lip shape, spur length, root characters, and fragrance timing are not documented in the available sources. Identification from a photograph or label alone is therefore limited; provenance, flower detail, and comparison with authenticated material are needed.

Native Range and Habitat

Angraecum crassum is native to Madagascar, with POWO giving the native range as northeastern Madagascar [1]. POWO records it in the wet tropical biome and describes it as an epiphytic subshrub [1]. IOSPE reports it from northeastern Madagascar at elevations from sea level to 400 m [3]; the Spanish Wikipedia entry gives 400 m [4]. Host trees, bark or rock substrate, microhabitat, and local seasonality are not documented in the supplied evidence beyond the general epiphytic habit. The sources describe native occurrence only; no introduced or naturalized records were supplied.

Species-Specific Care

The care evidence for this species is sparse. The table below separates what is documented from what is not; it does not convert native elevation into greenhouse setpoints or assume that other Angraecum species provide a template.

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The only cultivation descriptor with species-specific support is IOSPE’s phrase hot growing, tied to its report of sea level to 400 m [3]. That phrase is not a formal temperature group and does not establish exact temperatures. Because the plant is documented as epiphytic [1][3], growers may reasonably ask about mounting or open media, but the supplied evidence does not specify a method, medium, pot size, or watering regime. No dry rest, humidity target, or fertilizer schedule should be inferred from its native elevation or from unrelated Angraecum accounts. The conflicting flowering months also mean that bloom timing should be recorded for the individual plant and growing context rather than treated as a care calendar.

Flowering and Pollination

IOSPE reports flowering in later winter, spring, and early summer on a 7.2 inch (18 cm) inflorescence with 5 to 12 flowers [3]. It does not state whether those months refer to the southern hemisphere, a greenhouse, or another growing context, so the report should be treated as a horticultural observation rather than a universal season. The Spanish Wikipedia entry says spring to autumn [4], and NativePlants.info says January through December [5]; these are incompatible summaries and are not averaged here. IOSPE describes the flowers as thick, fleshy, about 4 cm across, and turning yellow with age [3]. NativePlants.info lists the species as fragrant, but the supplied IOSPE and Spanish snippets do not corroborate fragrance or its timing [5]. Flower longevity, nectar spur dimensions, and pollinators are not documented in the available sources. No pollinator should be inferred from flower shape alone.

Conservation and Responsible Cultivation

No formal IUCN Red List assessment is present in the supplied evidence. POWO’s general-information page includes an Angiosperm Extinction Risk Predictions v1 entry that predicts the species as threatened with low confidence [2]. That is a model-based prediction, not a formal conservation status, and it should not be presented as an IUCN category. Habitat-loss details, population size, trade pressure, and legal status are not documented in the supplied sources. A nursery purchase should not be assumed to be legally compliant without separate evidence.

Evidence and Limitations

This profile relies on search snippets and short page excerpts, not full-page or full-paper verification. The accepted name and native range are supported by POWO [1]. Most morphological and flowering details come from IOSPE [3], with a conflicting secondary summary from Spanish Wikipedia [4] and additional conflicting flower-color and bloom-month data from NativePlants.info [5]. The publication date is inconsistent between POWO’s 1809 record and the 1822 date used by horticultural sources [1][3][4]. No verified photographs, herbarium specimen images, pollinator observations, formal conservation assessment, or detailed cultivation trial were supplied. Care recommendations beyond the cautious hot growing descriptor remain Not documented.