| Spruceanthus theobromae | |
|---|---|
Scientific classification  | |
| Kingdom: | Plantae |
| Division: | Marchantiophyta |
| Class: | Jungermanniopsida |
| Order: | Porellales |
| Family: | Lejeuneaceae |
| Genus: | Spruceanthus |
| Species: | S. theobromae |
| Binomial name | |
| Spruceanthus theobromae | |
| Synonyms [2] | |
| |
Spruceanthus theobromae is a species of liverwort in the family Lejeuneaceae. It is endemic to Ecuador, where it is the only liverwort species known to be endemic to the western foothills of the Ecuadorian Andes. [3]
The species was first discovered and described by Richard Spruce as Lejeunea theobromae in 1884, publishing his findings in the Transactions & Proceedings of the Botanical Society of Edinburgh. In 1893, Victor Schiffner reclassified it as Ptychanthus theobromae in Engler and Prantl's work Die Natürlichen Pflanzenfamilien. Finally, in 1985, S. Rob Gradstein established its current classification as Spruceanthus theobromae. The type specimen was collected by Spruce from the bark of a cacao tree ( Theobroma ) near the Rio Ventana close to Guayaquil in Los Rios Province, Ecuador. Type specimens are preserved in the herbaria of Geneva (G), Manchester (MANCH 17343, 17344), and Vienna (W). [4]
Spruceanthus theobromae is a robust liverwort that grows on tree bark, forming loosely ascending or possibly hanging stems that measure 3–3.5 millimetres in width. When dry, the plant appears brownish-green in colour. The plant's branching pattern follows the Lejeunea -type structure, with fertile plants developing fork-like divisions. The lower portions of the stem feature curved, whip-like branches. The stem itself is sturdy, composed of approximately 35 outer (epidermal) cells surrounding more than 100 inner ( medullary ) cells, with the outer layers having thicker, brown-pigmented walls while the inner portions remain colourless. [4]
The leaves are widely spread when dry and slightly overlapping. Each leaf has a roughly oblong shape, measuring 1.8–2.2 mm long by 1.2–1.4 mm wide, with rounded or slightly pointed tips. The leaf cells are notably elongated and contain very small, irregularly star-shaped thickenings (trigones) where cells meet. The underleaves (modified leaves on the lower surface) are relatively small, spaced apart, and roughly circular or transversely oval in shape. [4]
The species is capable of producing both male and female reproductive structures on the same plant (autoicous) or in close proximity (paroicous). Male reproductive structures (androecia) form on short side branches or the main stem, while female structures (gynoecia) develop with 1–2 innovations (new growth) below them. The perianth (protective structure around the developing sporophyte extends well beyond the surrounding leaves and features 5–8 ridges or keels . [4]
When present, the spores are round and feature distinctive rosette patterns. The spore capsules contain specialised cells called elaters (approximately 72 per capsule) that help disperse the spores, each marked by a single spiral pattern. No methods of vegetative reproduction (reproduction without spores) have been observed to occur in this species. [4]
The species occurs in a narrow corridor at the western base of the Andes between 100–300 m (330–980 ft) elevation, in areas characterized by frequent morning fog and high annual rainfall exceeding 2,500 mm (98 in). It thrives in tropical equatorial conditions with temperatures between 23–25 °C (73–77 °F). The species is found across approximately 400 km2 (150 sq mi) of land, primarily in cacao plantations. [3]
Spruceanthus theobromae shows unusual host specificity among tropical bryophytes, growing almost exclusively on the trunk bases of Theobroma cacao (cacao trees) that are older than 20 years. It shows a preference for moist habitats with periodic inundation and is typically found in plantations with low to moderate management intensity. The species is classified as a "perennial shuttle species" based on its life strategy characteristics. [3]
The species is monoicous (having both male and female reproductive structures on the same plant) and reproduces frequently through sexual means, with no observed asexual reproduction. Its spores measure 30–40 × 25 × 35 μm. [3]
Spruceanthus theobromae commonly grows alongside other bryophytes including Bryopteris filicina , Ceratolejeunea cornuta , C. cubensis , Fissidens minutus , and Neckeropsis undulata . It shows a negative association with drought-tolerant species such as Lejeunea laetevirens . [3]
Initially reported from only five tree trunks at a single site, a 2000 IUCN assessment classified it as Critically Endangered. [1] However, a 2001 study found the species at 12 different cacao plantations and suggested reclassification as Near Threatened. [3]
The species faces several conservation challenges. It is unique as the only epiphytic liverwort in tropical America recorded exclusively from plantations. Its survival depends heavily on the continuation of cacao plantations with low management intensity. Local farming practices, particularly "limpia" (the removal of epiphytes from trees), pose a significant threat to populations. The species' habitat has been significantly impacted by deforestation, with less than 4% of the original forest cover remaining in the region since the late 1950s. [3]
Bryophytes are a group of land plants (embryophytes), sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants: the liverworts, hornworts, and mosses. In the strict sense, the division Bryophyta consists of the mosses only. Bryophytes are characteristically limited in size and prefer moist habitats although some species can survive in drier environments. The bryophytes consist of about 20,000 plant species. Bryophytes produce enclosed reproductive structures, but they do not produce flowers or seeds. They reproduce sexually by spores and asexually by fragmentation or the production of gemmae.
The Marchantiophyta are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of genetic information.
Fissidens adianthoides, the maidenhair pocketmoss, is a moss in the family Fissidentaceae. It was first collected by Hedwig in 1801.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur.
Moniliophthora perniciosa is a fungus that causes "witches' broom disease" (WBD) of the cocoa tree T. cacao. This pathogen is currently limited to South America, Panama and the Caribbean, and is perhaps one of the best-known cocoa diseases, thought to have co-evolved with cocoa in its centre of origin.
Caudalejeunea grolleana is a species of liverwort in the family Lejeuneaceae. It is endemic to Madagascar. Its natural habitat is subtropical or tropical dry forests. It is threatened by habitat loss. This liverwort occurs on tree bark and dead wood in undisturbed lowland rainforest. The main threat to the species is deforestation. Its habitat in Madagascar has a tropical to subtropical climate.
Fulfordianthus evansii is a species of liverwort in the family Lejeuneaceae. It is found in Belize, Costa Rica, Guatemala, and Panama. Its natural habitat is subtropical or tropical moist lowland forests.
Haesselia roraimensis is a species of liverwort in the family Cephaloziaceae. It is endemic to Guyana. Its natural habitat is on rotten logs in periodically flooded riverine forest from 550 to 1,550 metres elevation, in the humid submontane tropical 'mossy' forests on the slopes of Mount Roraima, where the borders of Brazil, Venezuela, and Guyana meet.
Colura irrorata is a species of liverwort in family Lejeuneaceae. It is endemic to Ecuador. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss. The species was previously known as Myriocolea irrorata, but was transferred to Colura in 2012 following a phylogenetic analysis of nuclear and plastid molecular markers and a reinterpretation of morphological characters.
Radula jonesii is a species of liverwort in the family Radulaceae. It is known from a few locations on Madeira and one location on Tenerife. The populations are small and vulnerable.
Schistochila macrodonta is a endangered species of liverwort in the family Schistochilaceae. It is found in Bhutan and China. This large, unbranched liverwort, characterised by its shoots measuring 4–6 centimeters in length and distinctive two-lobed leaves with smooth margins, is found only in high-altitude temperate and subtropical forests of Bhutan and China's Yunnan Province, at elevations between 2,730 and 3,580 metres. The species has reddish-brown rhizoids and the unusual presence of bicellular propagules at its leaf tips. Its extremely restricted distribution, known from only a few locations spanning less than 500 square kilometres, has led to its classification as endangered on the IUCN Red List due to ongoing habitat decline.
Lejeunea drehwaldii, synonym Sphaerolejeunea umbilicata, is a species of liverwort in the family Lejeuneaceae. It is endemic to Colombia. Its natural habitat is subtropical or tropical moist lowland forests.
Symbiezidium madagascariense is a species of liverwort in the family Lejeuneaceae native to Madagascar and Seychelles. It is considered an endangered species.
Lejeunea hodgsoniana is a species of liverwort in the family Lejeuneaceae. Endemic to New Zealand, it was first recognized in 1980 but not formally described until 2013. The plant forms bright green mats up to 7 centimetres in diameter on tree bark and occasionally on rocks. The species is found from the Kermadec Islands in the north to the Chatham Islands in the south, primarily in coastal and lowland areas below 100 metres elevation. It is distinguished from related species by its relatively large size, multi-celled tooth on the leaf lobule, and deeply divided underleaves with pointed tips. While showing a particular affinity for mahoe trees, it grows on various native and introduced trees and is considered "Not Threatened" under the New Zealand Threat Classification System due to its abundance within its range and ability to grow in both pristine and disturbed habitats.
Radula demissa is a species of liverwort in the family Radulaceae. It occurs in southeastern Australia and New Zealand, where it grows as an epiphyte in temperate rainforest environments.
Pogonatum urnigerum is a species of moss in the family Polytrichaceae, commonly called urn haircap. The name comes from "urna" meaning "urn" and "gerere" meaning "to bear" which is believed to be a reference made towards the plant's wide-mouthed capsule. It can be found on gravelly banks or similar habitats and can be identified by the blue tinge to the overall green colour. The stem of this moss is wine red and it has rhizoids that keep the moss anchored to substrates. It is an acrocarpous moss that grows vertically with an archegonium borne at the top of each fertilized female gametophyte shoot which develops an erect sporophyte.
Drepanolejeunea senticosa is a critically endangered species of liverwort in the family Lejeuneaceae, endemic to Cuba. The species is epiphyllous, meaning it grows on the surfaces of living leaves, and is found in subtropical/tropical moist lowland forest habitats. While male specimens have been frequently observed, the species' perianth and capsule remain undescribed.
Trichocolea tomentella is a species of liverwort belonging to the family Trichocoleaceae. It forms loose, pale green to yellowish-white mats and is characterised by its highly divided leaves that give it a feathery or fuzzy appearance. The species has a wide distribution across temperate regions of the Northern Hemisphere, particularly in oceanic and suboceanic areas, occurring in Europe, Asia, North Africa, and eastern North America. It typically grows in moist, shaded locations, especially near springs and streams in deciduous and coniferous forests. While capable of sexual reproduction, with male and female structures on separate plants, it reproduces predominantly through vegetative means via branching and fragmentation. The species shows considerable morphological variation between populations but maintains stable taxonomic characteristics in its cell structure. Though it can form extensive pure patches and effectively compete with other bryophytes in suitable habitats, T. tomentella faces threats from habitat destruction, particularly through logging and drainage of its preferred moist forest habitats.
Nowellia curvifolia is a species of liverwort belonging to the family Cephaloziaceae. It is a small, delicate plant that forms prostrate growths on rotting logs in forests throughout the northern temperate and subarctic regions. The species is distinguished by its distinctive billowed leaves arranged in two rows, each divided into two pointed lobes with the lower lobe forming a specialised water-holding pocket called a water-sac. The plant shows seasonal colour variation from rose to purple to brown to spring green, developing reddish-purple pigmentation in autumn and winter. It reproduces both sexually, through spores produced in reddish-brown capsules, and asexually via single-celled gemmae. N. curvifolia serves as an indicator species in forest ecosystems, particularly in montane spruce-fir forests, where it often forms pure mats on decorticated logs and is associated with the slime mould species Barbeyella minutissima.
Lejeunea mandonii, also known as Atlantic lejeunea is a species of liverwort from the Lejeuneaceae family.
