Carex pilulifera
Species of grass-like plant
From Wikipedia, the free encyclopedia
Carex pilulifera, the pill sedge,[2] is a European species of sedge found in acid heaths, woods, and grassland from Macaronesia to Scandinavia. It grows up to 30 cm (12 in) tall, with 2–4 female spikes and 1 male spike in an inflorescence. These stalks bend as the seeds ripen, and the seeds are collected and dispersed by ants of the species Myrmica ruginodis.
| Carex pilulifera | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Embryophytes |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Clade: | Commelinids |
| Order: | Poales |
| Family: | Cyperaceae |
| Genus: | Carex |
| Subgenus: | Carex subg. Carex |
| Section: | Carex sect. Acrocystis |
| Species: | C. pilulifera |
| Binomial name | |
| Carex pilulifera | |
| Synonyms[1] | |
| |
Description

The culms of Carex pilulifera grow to a length of 8–30 centimetres (3–12 in), and are often noticeably curved.[3] The leaves are 5–20 cm (2–8 in) long and 1.5–2.0 millimetres (0.06–0.08 in) wide, and are fairly flat.[3] The rhizomes of C. pilulifera are very short, giving the plant a caespitose (densely tufted) appearance.[3] The tussock grows outwards through the production of annual side-shoots.[4]
The inflorescence comprises a single, terminal, male (staminate) spike, and 2–4 lateral female (pistillate) spikes.[3] The spikes are clustered together, and the whole inflorescence is 1–4 cm (0.4–1.6 in) long.[3] The female spikes are 4–8 mm (0.16–0.31 in) long, ovoid or approaching spherical,[3] and contain 5–15 flowers.[4] The female spikes are directly attached to the stem, where each is subtended by a bract that does not form a sheath.[3] The male spike is 8–15 mm (0.3–0.6 in) long and much narrower.[3]
Distribution and ecology
Carex pilulifera has a wide distribution in Europe, extending from Macaronesia (Azores and Madeira) and the northern Balkan Peninsula to Scandinavia and northern European Russia.[5][1] It grows on acidic substrates including heathland, grassland , and woodland.[4] It typically inhabits soils with a pH of 4.5–6.0.[3]
As the seeds of C. pilulifera ripen, the culms bend and can eventually touch the ground.[4] The seeds are then dispersed by ants, particularly Myrmica ruginodis,[4] in a process known as myrmecochory, and are eaten by other insects, such as the ground beetle Harpalus fuliginosus.[4]
Subspecies
Two subspecies are accepted.[1]
- Carex pilulifera subsp. azorica (J.Gay) Franco & Rocha Afonso (synonym Carex azorica J.Gay) – Azores
- Carex pilulifera subsp. pilulifera (synonyms Carex aederi Desv., Carex alba Bastard, Carex bastardiana DC., Carex decumbens Ehrh., Carex pullulans Dulac, and Carex saxumbra F.Lees)[6] – Europe and Madeira
Taxonomic history
Carex pilulifera was first described by Carl Linnaeus in his 1753 work Species Plantarum, which marks the starting point of botanical nomenclature.[5] The specific epithet pilulifera means "bearing small globular structures", in reference to the female spikes.[7]