Agrostylum is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 with about ninety species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 from the orchid family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 (Orchidaceae

Orchidaceae

The Orchidaceae, commonly referred to as the orchid family, is a morphologically diverse and widespread family of monocots in the order Asparagales. Along with the Asteraceae, it is one of the two largest families of flowering plants, with between 21,950 and 26,049 currently accepted species,...

). The genus name is derived from the Greek words agrostis ("grass") and phyllos ("leaf"), referring to the grass-like appearance of the leaves of some species.

These epiphytic

Epiphyte

An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...

 orchids occur in tropical

Tropics

The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately  N and the Tropic of Capricorn in the southern hemisphere at  S; these latitudes correspond to the axial tilt of the Earth...

 lowland forests, growing on trunks or branches of tress. They are found from the Seychelles

Seychelles

Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....

, Madagascar

Madagascar

The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...

, India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, Sri Lanka

Sri Lanka

Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...

, Malaysia, Indonesia

Indonesia

Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

 to the Pacific Islands

Pacific Islands

The Pacific Islands comprise 20,000 to 30,000 islands in the Pacific Ocean. The islands are also sometimes collectively called Oceania, although Oceania is sometimes defined as also including Australasia and the Malay Archipelago....

. The center of diversity is to be found in New Guinea

New Guinea

New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

, with at least 45 species.

These orchids have elongate, frequently pendulous stems

Plant stem

A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...

 with dense leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 that overlap at their base. They show peculiar, ball-like inflorescence

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

s of many bracts, bearing small flowers.

Species

There are four sections in this genus :

• Dolichodesme - elongated inflorescence which may have the form of a spike, but also may be partly branched as in a panicle.
• Eu-agrostophyllum – Leaves somewhat longer; small flowers on a shortened apical head; a few species may only develop one or two flowers.
• Oliganthe - characterised by a much elongated rhizome
  Rhizome
  In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
  
  and pendant sympodia. Leaves and flowers similar to those of the previous section.
• Appendiculopsis - slightly elongated, short creeping rhizomes; distichous, crowded, oblong leaves, at right angles with axis of stem, abruptly truncated at base, with a small petiole; terminal or lateral inflorescence; used to belong to the genus Appendicula.

• Agrostophyllum acutum (New Guinea).
• Agrostophyllum amboinense JMaluku - Ambon).
• Agrostophyllum appendiculoides (New Guinea).
• Agrostophyllum aristatum (Fiji).
• Agrostophyllum arundinaceum (Borneo).
• Agrostophyllum atrovirens (Maluku - Ambon).
• Agrostophyllum bilobolabellatum (Papua New Guinea).
• Agrostophyllum bimaculatum : Double-spotted Agrostophyllum (New Guinea).
• Agrostophyllum brachiatum (New Guinea).
  • Agrostophyllum brachiatum var. brachiatum (New Guinea).
  • Agrostophyllum brachiatum var. latibrachiatum (New Guinea).
• Agrostophyllum brevipes (E. Himalaya to Indo-China).
• Agrostophyllum callosum (Nepal to Hainan)
• Agrostophyllum compressum (New Guinea).
• Agrostophyllum crassicaule (New Guinea, Bismarck Archipel).
  • Agrostophyllum crassicaule var. bismarckiense (Bismarck Arch.)
  • Agrostophyllum crassicaule var. crassicaule (New Guinea).
• Agrostophyllum curvilabre (New Guinea to Solomon Is.).
• Agrostophyllum cyathiforme (W. Malaysia).
• Agrostophyllum cycloglossum (New Guinea).
• Agrostophyllum cyclopense (New Guinea).
• Agrostophyllum denbergeri (Sumatra to Java).
• Agrostophyllum dischorense (New Guinea).
• Agrostophyllum djararatense (Sumatra).
• Agrostophyllum dolychophyllum (New Guinea).
• Agrostophyllum earinoides (New Guinea).
• Agrostophyllum elatum (New Guinea).
• Agrostophyllum elmeri (Philippines).
• Agrostophyllum elongatum : Elongated Agrostophyllum (Malaysia to W. Pacific).
• Agrostophyllum fibrosum (New Guinea)..
• Agrostophyllum finisterrae (New Guinea).
• Agrostophyllum flavidum (Assam).
• Agrostophyllum fragrans (New Guinea).
• Agrostophyllum globiceps (W. Sumatra).
• Agrostophyllum globigerum (N. Borneo).
• Agrostophyllum glumaceum (W. Malaysia).
• Agrostophyllum graminifolium (New Guinea to Vanuatu).
• Agrostophyllum grandiflorum (New Guinea).
• Agrostophyllum indifferens ((Kalimantan).
• Agrostophyllum inocephalum (S. Taiwan to Philippines).
• Agrostophyllum javanicum (W. Malesia).
• Agrostophyllum kaniense (New Guinea).
• Agrostophyllum kusaiense (Caroline Is.).
• Agrostophyllum lamellatum (New Guinea).
• Agrostophyllum lampongense (Sumatra).
• Agrostophyllum laterale (Borneo).
• Agrostophyllum latilobum ( W. & C. Java).
• Agrostophyllum laxum (W. Malaysia).
• Agrostophyllum leucocephalum (New Guinea to SW. Pacific).
• Agrostophyllum leytense (Philippines).
• Agrostophyllum longifolium (Pen. Thailand to Malaysia.)
• Agrostophyllum longivaginatum (Philippines).
• Agrostophyllum luzonense (Philippines).
• Agrostophyllum macrocephalum (New Guinea).
• Agrostophyllum majus (Pen. Thailand to Vanuatu).
• Agrostophyllum malindangense (Philippines).
• Agrostophyllum mearnsii (N. Borneo to Philippines).
• Agrostophyllum megalurum (New Guinea to W. Pacific).
• Agrostophyllum merrillii (Philippines) .
• Agrostophyllum mindanense (Philippines).
• Agrostophyllum montanum : Mountain Agrostophyllum (New Guinea).
• Agrostophyllum mucronatum (New Guinea).
• Agrostophyllum myrianthum (Sikkim, Arunachal Pradesh).
• Agrostophyllum neoguinense (Papua New Guinea).
• Agrostophyllum niveum (New Guinea).
• Agrostophyllum occidentale (Seychelles, N. Madagascar).
• Agrostophyllum palawense (Caroline Is. - Palau).
• Agrostophyllum paniculatum ( New Guinea to Solomon Is. )
• Agrostophyllum papuanum (Papua New Guinea).
• Agrostophyllum parviflorum (Maluku to New Guinea).
• Agrostophyllum patentissimum (New Guinea).
• Agrostophyllum pelorioides (New Guinea).
• Agrostophyllum philippinense (Philippines).
• Agrostophyllum planicaule (Himalaya to Indo-China).
• Agrostophyllum potamophila : River-loving Agrostophyllum (New Guinea).
• Agrostophyllum rigidifolium (New Guinea).
• Agrostophyllum saccatilabium (Philippines).
• Agrostophyllum saccatum (Borneo)..
• Agrostophyllum sepikanum (New Guinea).
• Agrostophyllum seychellarum (Seychelles).
• Agrostophyllum simile (Sulawesi).
• Agrostophyllum spicatum (New Guinea).
• Agrostophyllum stenophyllum (New Guinea.).
• Agrostophyllum stipulatum (Indo-China, Malaysia to Solomon Is.)
  • Agrostophyllum stipulatum subsp. bicuspidatum (W. Malaysia).
  • Agrostophyllum stipulatum subsp. stipulatum (Indo-China, Malaysia to Solomon Is.)
• Agrostophyllum sumatranum (W. Sumatra, Borneo).
• Agrostophyllum superpositum (New Guinea to Solomon Is.).
• Agrostophyllum tenue (W. Malaysia)..
• Agrostophyllum torricellense (New Guinea to S. Vanuatu).
• Agrostophyllum trifidum (Sumatra, Borneo).
• Agrostophyllum uniflorum (New Guinea).
• Agrostophyllum vanhulstijnii (Maluku) .
• Agrostophyllum ventricosum (New Guinea).
• Agrostophyllum verruciferum (New Guinea).
• Agrostophyllum wenzelii (Philippines).
• Agrostophyllum zeylanicum (Sri Lanka).