#Aves

• Drummond's wattle — A dwarf species of ornamental shrub, endemic to the southwestern regions of Western Australia, renowned for its outstanding structural elegance. Unlike many acacia species that develop phyllodes, Acacia drummondii retains its true leaves, featuring a fine, delicate, evergreen, bipinnate foliage of a deep green hue. The plant is distinguished during its flowering season by its atypical, cylindrical, and pendulous inflorescences (resembling catkins or tassels) of an intense canary-yellow, making it considered one of the most refined and decorative small species within the genus.
• Acaena lucida — A species of perennial herbaceous plant in the Acaena genus, native to the cold and insular regions of the Southern Hemisphere (such as the Falkland Islands, Tierra del Fuego, and Magellanic regions). Its defining characteristic is the intense green foliage with an extremely glossy, smooth surface devoid of dense hairs, which strongly reflects light and gives the plant a fresh, vibrant appearance, ideal for groundcover in moist or partially shaded areas.
• Acaena pinnatifida — A species of perennial herbaceous plant in the Acaena genus, native to the temperate and subalpine regions of South America. The taxon stands out due to the deeply divided structure of its compound leaves, whose leaflets are deeply incised or pinnatifid, resembling miniature ferns. This unique foliar architecture not only enhances its aesthetic value but also represents an efficient structural adaptation for dissipating strong winds in its native habitats.
• Acaena splendens — A species of suffruticose perennial plant in the Acaena genus, native to the high mountainous zones of Chile and Argentina. This plant stands out for its exceptional aesthetics, being entirely covered by a dense indumentum of long, silky, appressed hairs, which give it an intensely glittering (shining) silvery appearance. This structural ecotype acts as an efficient thermal shield against severe nocturnal frosts and extreme ultraviolet radiation at high altitudes.
• Acalypha integrifolia — A species of shrub or small tree in the Acałypha genus, endemic to the islands of the western Indian Ocean (specifically the Mascarene Islands: Mauritius and Réunion). It is distinguished within its genus by its simple, lanceolate or elliptic leaves with entire (smooth, non-serrated) margins, a morphological characteristic directly reflected in its specific epithet. This plant is part of a vulnerable indigenous flora, adapted to the dry or transitional forest ecosystems of these insular regions.
• Acanthus — A perennial herbaceous plant in the Acanthus genus, Acanthaceae family, native to the Mediterranean region and tropical zones, characterized by large, deeply incised, often spiny leaves and tall spike-like inflorescences with white, purple, or pink flowers. In horticulture, it is cultivated as an ornamental backdrop plant due to its imposing architecture, being also the plant whose leaves served as the historical model for creating the famous architectural ornament of the Corinthian order.
• Acanthus — The type genus of the Acanthaceae family, comprising around 30 species of perennial herbaceous plants or shrubs native to the temperate and tropical regions of Southern Europe, Africa, and Asia. The plants are recognized by their majestic, deeply lobed, and frequently spiny leaves, and by their erect, dense flower spikes bearing bilabiate flowers. Its name holds immense cultural resonance, as its leaves served as the unchanging historical model for Corinthian and Composite architectural capitals.
• Acanthus longifolius — A species of perennial herbaceous plant in the Acanthus genus, Acanthaceae family, native to the Balkan Peninsula and neighboring regions of Southeastern Europe. It stands out for its unusually long, elegant, deeply and sinuously lobed leaves, which lack aggressive spines at their tips. This massive foliar structure forms a dense basal rosette from whose center rigid flower stalks rise in early summer, bearing spectacular spike-like inflorescences with white or purple bilabiate flowers framed by large, colorful bracts.
• Acanthus leaves — The plural form of the masculine noun 'acant'; it designates the ensemble of sculpted or painted ornamental elements that reproduce or stylize the leaves of the Mediterranean Acanthus plant. These decorative foliage reliefs are fundamental elements in the composition of Corinthian and Composite capitals in classical Greco-Roman architecture, repeated symmetrically and in tiers to create a dynamic visual effect of a natural crown.
• Acanthophilous — A plant morphological term used as an adjective to describe a plant displaying a strong ecological affinity for environments populated by spiny species, or whose leaves have partially or completely transformed into spines or thorns (a typical adaptation to drought). As a masculine noun, it defines a foliar anatomical structure evolutionarily modified into a sharp, rigid needle (as seen in cactus leaves or certain acacia species), serving to reduce water loss via transpiration and ensure self-defense.
• Acropachy — A rare pathological clinical syndrome characterized by the subperiosteal thickening and deformation of the long bones of the extremities, associated with soft tissue hypertrophy of the fingers and toes (clubbing / Hippocratic digits). This osteoarticular structural phenomenon occurs most frequently as an advanced extrathyroidal manifestation of Graves' disease (thyroid acropachy), typically coexisting with exophthalmos and pretibial myxedema.
• Actinology — An interdisciplinary branch of science dealing with the structural and theoretical study of luminous and electromagnetic radiation (particularly within the ultraviolet and short-wave visible spectrum) and the chemical, photochemical, or biological effects they produce on exposed bodies. Actinology encompasses principles from optical physics, photochemistry, and biophysics to analyze how radiant fluxes interact with organic and inorganic matter.
• Adenandra — A genus of perennial, shrubby plants native to the warm regions of South Africa, belonging to the Rutaceae family. These plants are structurally characterized by small, often aromatic leaves due to prominent oil glands, and decorative flowers with five petals shaded in white or pink, being cultivated internationally as ornamental plants due to their resilience in sandy soils.
• Adenophyllous — Having a specific structural affinity for glandular tissues; in botany, it describes leaves or plant organs covered with glandular hairs, capable of secreting resins, essential oils, or mucilaginous substances. This morphological term defines the ecological adaptations of certain plants intended for parasite protection or water retention.
• Adenostyles tomentosa — A species of perennial, herbaceous plants belonging to the Asteraceae family, native to the mountainous regions of Central and Southern Europe (particularly the Alps, Apennines, and Carpathians). This plant is structurally recognized by its large, cordate leaves covered on the underside with a dense, white-felty pubescence (tomentum), and by its purple capitula-type inflorescences, adapted to the humid climate of montane forests and alpine meadows.
• Adiantopsis pedata — A species of small terrestrial fern belonging to the Pteridaceae family, native to neotropical regions, particularly the Caribbean islands (such as Jamaica) and parts of South America. The plant is structurally recognized for its unique pedately divided leaves, with fine segments arranged like toes, attached to thin, black, shiny stipes (petioles), developing optimally in shaded limestone soils.
• Adiantum — A genus of ferns in the family Pteridaceae, comprising approximately 250 species commonly known as maidenhair ferns; they are structurally characterized by black, shiny, hair-thin petioles supporting delicate fronds with flabelliform (fan-shaped) segments that shed water droplets. These plants are distributed globally across tropical and warm temperate zones, preferring damp rocks near waterfalls.
• Adromischus — A genus of dwarf succulent plants in the Crassulaceae family, native to the arid zones of Southern Africa and Namibia, characterized by extremely fleshy leaves with spectacular shapes and varied textures. Its name comes from Greek, combining 'hadros' (thick, robust) and 'mischos' (stem, stalk), referring directly to the thick stem or petiole of these species, highly prized by collectors for their morphological diversity.
• Adromischus clavifolius — A species or variety of dwarf succulent plant (also known scientifically as Adromischus cristatus var. clavifolius), native to the Eastern Cape Province of South Africa, remarkable for its unique club-shaped or wedge-shaped leaves grouped compactly. The specific epithet 'clavifolius' stems from the Latin words 'clava' (club, nail) and 'folium' (leaf), referring to the swollen profile of its silver-green leaves which often turn reddish under the sun, and a short stem covered in dense reddish aerial roots.
• Adromischus marianae — An extremely variable and highly prized dwarf perennial succulent plant species within the Crassulaceae family, endemic to the Namaqualand region of South Africa. Characterized by its very slow growth rate and unique, rough, warty, or heavily textured leaves, it often mimics dried raisins or rocky coral structures. The species encompasses numerous globally famous forms and cultivars (such as 'herrei', 'hallii', or 'Little Spheroid'), whose coloration ranges spectacularly from lime green to brick red and deep purple depending on sun exposure.