''Romulea toximontana'' is low a herbaceous perennial

geophyte A storage organ is a part of a plant specifically modified for storage of energy (generally in the form of carbohydrates) or water. Storage organs often grow underground, where they are better protected from attack by herbivores. Plants that have ...

in the family

Iridaceae Iridaceae is a family of plants in order Asparagales, taking its name from the irises, meaning rainbow, referring to its many colours. There are 66 accepted genera with a total of c. 2244 species worldwide (Christenhusz & Byng 2016). It include ...

native to

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

. It has a small

corm A corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen underground plant stem that serves as a storage organ that some plants use to survive winter or other adverse conditions such as summer drought and heat (perennation). The word ' ...

in the soil, several linear leaves, white

trimerous Merosity (from the greek "méros," which means "having parts") refers to the number of component parts in a distinct whorl of a plant structure. The term is most commonly used in the context of a flower where it refers to the number of sepals in a ...

flowers, yolk-yellow near the centre and with a purple wash on the outside. The 1997

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

of Threatened Plants lists this species as rare.

Taxonomy

''Romulea toximontana'' was described by South African botanist and expert in bulbous plants Miriam de Vos in 1972. It has been assigned to the

section Section, Sectioning or Sectioned may refer to: Arts, entertainment and media * Section (music), a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents ** Section sign ...

''Ciliatae'', a part of the

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

''Spatalanthus''.

Description

''Romulea toximontana'' is a low

perennial plant A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

of high, that survives the dry southern summer through storage of its

resources Resource refers to all the materials available in our environment which are technologically accessible, economically feasible and culturally sustainable and help us to satisfy our needs and wants. Resources can broadly be classified upon their a ...

in an oval

. This corm is flattened obliquely and has a wide, fan-shaped ridge on the underside. Its stem may be entirely underground or reach a height of . The two lower leaves are about in diameter, have four narrow grooves along their length, and sometimes rows of very small, evenly spaced hairs (or

ciliate The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagellum, eukaryotic flagella, but are in general shorter and present in much larger numbers, with a ...

). Each flower is subtended by two bracts. The outer bract has a narrow papery margin, while the inner one has a wide papery margin with a brown edge. The flowers do not smell and are white on the inside, yolk yellow near the centre, and have a purple wash on the outside of the six elliptic

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s of long. The

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s consist of long filaments topped by long anthers. When the fruit is ripe the flower stalk spreads widely. This species flowers in August.

Differences with related species

''R. toximontana'' and '' R. montana'' share the same type of corm, both having a very broad ridge on their underside, and fruiting stems spread out. ''R. montana'' however has yellow flowers with dark blotches or streaks in the throat while in ''R. toximontana'' the white flowers are yellow down the cup, while the outside of the tepals is purple. ''R. toximontana'' can be confused with '' R. sladenii'' because it also has white flowers and grows in the same environment on the Gifberg. The stamens of ''R. sladenii'' rise just beyond the floral cup whereas the stamens in ''R. toximontana'' are entirely contained. To be absolutely certain of the identification, the corms need to be examined. ''R. sladenii'' has symmetrical, bell-shaped corms with a lacerated ridge on the bottom, where ''R. toximontana'' has obliquely flattened corms and a wide, fan-shaped ridge.

Distribution

''Romulea toximontana'' is only known from a small area on the Bokkeveld plateau, the Gifberg and the Matsikamma Mountains, all near

Vanrhynsdorp Van Rhynsdorp (Afrikaans: Vanrhynsdorp) is a settlement in West Coast District Municipality in the Western Cape province of South Africa. Van Rhynsdorp was founded as Trutro ("TroeTroe") after the area was first explored by Europeans in 1661 by P ...

Ecology

''Romulea toximontana'' grows on sandy soils and weathered sandstone.

References

{{Taxonbar, from=Q15580798 Endemic flora of South Africa toximontana Plants described in 1972