Phytelephas seemannii

The species epithet seemannii honors botanist Berthold Carl Seemann who collected some of the first specimens, including the lectotype.[4] In Spanish it is called cabeza de negra (black head), palma de marfil (ivory palm), and tagua.[5] In Colombian Spanish it is additionally known as allagua.[5] In Cuna it is sam,[3] or sagu.[5] In both the Quechua[3] and Choco languages it is called anta.[5]

Phytelephas seemannii is native to Colombia and Panama, with much of it growing in shaded areas by rivers in lowland rainforest in Colombia's Pacific/Chocó natural region.[1][4] It is usually found at elevations from 0–1,000 metres (0–3,281 ft) in semi-deciduous forests.[3]

Phytelephas seemannii has two subspecies, P. s. ssp. brevipes and P. s. ssp. seemannii.[3] P. s. ssp. brevipes is endemic to the upper Mamoní Valley in Panama, at or below 500 metres (1,600 ft) in elevation, and may be a hybrid of P. seemannii and P. macrocarpa.[3]

Phytelephas seemannii most closely resembles Phytelephas macrocarpa.[2] However, the former has leaves that have fewer pinnae which are larger.[2] Its trunk is also not upright but "creeping" and decumbent.[2] The tree is generally less than 1 metre (3 ft 3 in) tall, with inflorescences below the 0.5 metres (1 ft 8 in) mark.[6] Its spathes are double instead of in threes or fours.[2] On the male flowers are only 36 stamens and not the hundreds of other species.[2] The heads contain fewer fruits than other species, but inside are more nuts that are larger.[2] Typically each fruit has 5 seeds protected by a 1 centimetre (0.39 in) fibrous coat, and each inflorescence has up to 8 fruits.[6] Each tree can have dozens of inflorescences at a time.[6]

In immature seeds, the endosperm is a liquid, like in a coconut, and then later it hardens as the fruit wall softens and deteriorates.[6]

Panama ivory palm trees flower after the end of the dry season, between February and May.[7] The flowers are pollinated by insects, specifically by two types of rove beetles, pollen-eating Amazoncharis spp. and their predators in the genus Xanthopygus.[7] The Amazoncharis beetles hollow out egg chambers within the male inflorescence, similar to how beetles in the related subtribe Gyrophaenina do inside of mushrooms.[7] Squirrels and agoutis will eat the fleshy inner mesocarp surrounding the endocarp of the fruit, but do not eat the extremely hard endosperm.[6] The rock-hard endosperm also makes the seed immune from most insect pests.[6] Seed dispersers include the Central American agouti (Dasyprocta punctata),[6] and lowland paca (Agouti paca).[8][6]

The seeds are traded at a regional international level as vegetable ivory,[1] which is also called tagua. This commercial use is a threat to the species, but progress is being made on using more sustainable practices and conservation.[1] As the tree typically grows only 1 metre (3 ft 3 in) tall, it fortunately was not chopped down to harvest the seeds as was done with Phytelephas aequatorialis at the peak of tagua harvesting.[6]

The jelly-like liquid in the immature seeds, which later turns into the vegetable ivory, is edible.[5] Occasionally in the marketplaces of Guna Yala the thin crust surrounding the ivory is sold as food.[5]

In Colombia the fronds are sometimes used for thatch.[5]

• Media related to Phytelephas seemannii at Wikimedia Commons
• Data related to Phytelephas seemannii at Wikispecies