Alcea


Alcea is a genus of over 80 species of flowering plants in the mallow family Malvaceae, commonly known as the hollyhocks. They are native to Asia and Europe. The single species of hollyhock from the Americas, the streambank wild hollyhock, belongs to a different genus.

Description

Hollyhocks are annual, biennial, or perennial plants usually taking an erect, unbranched form. The herbage usually has a coating of star-shaped hairs. The leaf blades are often lobed or toothed, and are borne on long petioles. The flowers may be solitary or arranged in fascicles or racemes. The notched petals are usually over three centimeters wide and may be pink, white, purple, or yellow. The fruit is a schizocarp, a dry disc divided into over 15 sections that contain seeds.

Species

The following species are accepted:
  • Alcea abchazica Iljin
  • Alcea acaulis Alef.
  • Alcea afghanica I.Riedl
  • Alcea antoninae Iljin
  • Alcea apterocarpa Boiss.
  • Alcea arbelensis Boiss. & Hausskn.
  • Alcea assadii Pakravan
  • Alcea aucheri Alef.
  • Alcea baldshuanica Iljin
  • Alcea biennis Winterl
  • Alcea calvertii Boiss.
  • Alcea chrysantha Zohary
  • Alcea damascena Mouterde
  • Alcea denudata Boiss.
  • Alcea digitata Alef.
  • Alcea dissecta Zohary
  • Alcea djahromi Parsa
  • Alcea excubita Iljin
  • Alcea fasciculiflora Zohary
  • Alcea ficifolia L. – Antwerp hollyhock
  • Alcea flavovirens Iljin
  • Alcea freyniana Iljin
  • Alcea froloviana Iljin
  • Alcea galilaea Zohary
  • Alcea ghahremanii Pakravan & Assadi
  • Alcea gorganica Zohary
  • Alcea heldreichii Boiss.
  • Alcea hohenackeri Boiss.
  • Alcea hyrcana Grossh.
  • Alcea ilamica Pakravan
  • Alcea iranshahrii Pakravan, Ghahr. & Assadi
  • Alcea karakalensis Freyn
  • Alcea karsiana Litv.
  • Alcea koelzii I.Riedl
  • Alcea kopetdaghensis Iljin
  • Alcea kuhsanguia Parsa
  • Alcea kurdica Alef.
  • Alcea kusjariensis Iljin
  • Alcea lasiocalycina Boiss.
  • Alcea lavateriflora Boiss.
  • Alcea lenkoranica Iljin
  • Alcea litvinovii Iljin
  • Alcea loftusii Zohary
  • Alcea longipedicellata I.Riedl
  • Alcea mazandaranica Pakravan & Ghahr.
  • Alcea mosulensis I.Riedl
  • Alcea mozaffarianii Ghahr. & Pakravan & Assadi
  • Alcea nikitinii Iljin
  • Alcea nudiflora Boiss.
  • Alcea peduncularis Boiss. & Hausskn.
  • Alcea pisidica Hub.-Mor.
  • Alcea popovii Iljin
  • Alcea rechingeri I.Riedl
  • Alcea remotiflora Alef.
  • Alcea rhyticarpa Iljin
  • Alcea rosea L. – common hollyhock
  • Alcea rosulata I.Riedl
  • Alcea rufescens Boiss.
  • Alcea rugosa Alef.
  • Alcea scabridula I.Riedl
  • Alcea schirazana Alef.
  • Alcea semnanica Pakravan
  • Alcea setosa Alef. – bristly hollyhock
  • Alcea sophiae Iljin
  • Alcea sosnovskyi Iljin
  • Alcea sotudehi Parsa
  • Alcea striata Alef.
  • Alcea sulphurea Alef.
  • Alcea sycophylla Iljin & V.V.Nikitin
  • Alcea tabrisiana Iljin
  • Alcea talassica Iljin
  • Alcea tarica Pakravan & Ghahr.
  • Alcea teheranica Parsa
  • Alcea tholozanii Stapf
  • Alcea transcaucasica Iljin
  • Alcea turcomanica Iljin
  • Alcea turkeviczii Iljin
  • Alcea vameghii Parsa
  • Alcea wilhelminae I.Riedl
  • Alcea woronowii Iljin
  • Alcea xanthochlora I.Riedl

    Uses

Hollyhocks are popular garden ornamental plants. They are easily grown from seed. Breeds with red flowers attract hummingbirds and butterflies. Cultivars have been bred, especially from A. rosea. They include the double-flowered 'Chater's Double', the raspberry-colored 'Creme de Cassis', and 'The Watchman', which has dark, nearly black, maroon flowers.
The stems of hollyhocks can be used as firewood, and the roots have been used medicinally.

Pests and diseases

Alcea species are used as food plants by the larvae of some Lepidoptera species including Bucculatrix quadrigemina and Vanessa cardui, the painted lady.
The mallow flea beetle is a pest that makes tiny holes in the leaves. Cutworms, aphids, and capsid bugs use the plant as a food source in hotter and drier conditions. A number of weevils use A. rosea as their host plant, including Rhopalapion longirostre, Alocentron curvirostre, and Aspidapion validum.
The plants are also susceptible to the pathogenic fungus Puccinia malvacearum, the hollyhock rust.

Culture

The Aoi Matsuri is one of the three main festivals of the city of Kyoto.
During the Victorian era, the hollyhock symbolized both ambition and fecundity in the language of flowers.
The UK National Collection of hollyhocks is held by Jonathan Sheppard in Lincolnshire.