Commelinaceae Research: Terminology, glossary

Glossary and terms that are used often when describing Commelinaceae plants

(reflecting my current research and the research of other experienced collectors on the Commelinaceae family, its varieties, cultivars, hybrids and terms used and discussed.

Created: Nov. 20, 2020

Updated: Mar. 10, 2022

acuminate leaf tip

acuminate: reference to the shape of the leaf tip, which is tapering to a long point in a concave manner.

acute (leaf tip or base)

acute: reference to the leaf tip or base that is pointed, having a short sharp apex angled less than 90°.

aff. affin.: species affinis (commonly abbreviated as: sp. aff. or sp. or aff. or affin. ) is taxonomic terminology in zoology and botany. In open nomenclature it indicates that available material or evidence suggests that the proposed species is related to, has an affinity to, but is not identical to, the species with the binomial name it comes after. The Latin word affinis can be translated as "closely related to", or "akin to". Example: Tradescantia aff. umbraculifera.

albiflora: synonym for Tradescantia fluminensis^[1]. Most of the cultivated varieties we see as albiflora are actually hybrids that resemble a crossing between T. fluminensis x T. cerinthoides (however we are not sure of their actual parentage). But there is no such thing as an "albiflora group". Because a) albiflora is a species epithet that is a synonym, and b) since these plants are hybrids the taxon name albiflora cannot be used when speaking about cultivated varieties.

albolineatus, -a, -um: (botany) Marked longitudinally with white depressed parallel lines. Etym. <albus (white in Latin) + lineatus (marked by fine parallel lines)>. Example: Syngonium podophyllum var. albolineatum. #You can find all the terms concerning variegation in the page: Variegated plants and their names.

albostriatus, -a, -um: a plant whose variegation is consisted of white stripes. Etym. <albus (white in Latin) + striatus (having stripes)>. Example: Tradescantia aff. fluminensis 'Albostriata'.

albovariegatus, -a, -um: a plant with white variegation. Etym. <albus (white in Latin) + variegatus (a variegated plant)>. Example: Tradescantia aff. fluminensis 'Albovariegata'.

albus, -a, -um: it means white in Latin^[2].

aureolineatus, -a, -um: (botany) Marked longitudinally with golden (yellow) depressed parallel lines. Example: Cortaderia selloana ‘Aureolineata’.

aureostriatus, -a, -um: a plant whose variegation is consisted of yellow (golden) stripes. Etym. <aureus (golden in Latin) + striatus (having stripes)>. This term is used only for cultivars.

aureovariegatus, -a, -um: a plant with yellow (golden) variegation. Etym. <aureus (golden in Latin) + variegatus (a variegated plant)>. This term is used only for cultivars. Example: Tradescantia spathacea 'Aureostriata'.

The axil angle/distance from leaf to stem

axil: the angle between the upper side of a leaf or stem and the supporting stem or branch.

binate: double; growing in pairs or couples. Third-person singular simple present binates, present participle binating, simple past and past participle binated.

blossfeldiana: synonym for Tradescantia cerinthoides^[3].

Bracts look like small leaves, enveloping the flower/inflorescence.

bract: usually in plural bracts are modified, usually small, leaf-like structure often positioned beneath a flower or inflorescence. What are often taken to be the petals of flowers are sometimes bracts.

concolor: having one color. Example: Tradescantia spathacea f. concolor.

congesta: nom. illeg. falsely used as a species name ie: ~~Callisia congesta~~ to describe the accepted botanical species Callisia soconuscensis, and with common name Dragon Tail^[4].

Gibasis pellucida inflorescence, showing the scorpioid cyme.

cincinnus (plural cincinni): a type of monochasium on which the successive axes arise alternately in respect to the preceding one; a scorpioid cyme. Etymology: ancient Greek: κίκιννος (kíkinnos) a curled lock of hair^[19].

cultivar/cultigen/cv.: a cultivar (or cultigen or horticultural variety) with the abbreviation cv. is a cultivated variety that originated after human intervention. The names of cultivars are quoted using single quotes '. . .' and the first letter of each name is capitalized. Example: Murdannia ‘Bright Star’. Murdannia ‘Bright Star’ is a horticultural cultivar with unique characteristics that can only be found combined in that specific cultivar. In the past the denomination cv. used to be included in the name ie: Murdannia cv. ‘Bright Star’ but that is currently not accepted.

Cyanotis: genus in the Commelinaceae family with - currently - 50 accepted species^[9]. Etymology: ancient Greek κυανός (blue, cyan, azure) + ancient Greek οὖς (ear) + the suffix -ις (also -ίδα in modern Greek, hence it's a feminine name)^{[10, 11]}. It refers to the blue color of the flowers in this genus^[12].

cyme: the main kind of cymose inflorescence is the cyme . Cymes are further divided into various types, according to the structure of the inflorescence. The slideshow below helps to have a better visualization of what each term refers to:

discolor: (1) foliage with dull/less colors/foliage with separate colors. (2) foliage that was reverted. Such as in the case of Tradescantia zebrina var. discolor 'Multicolor' that was kept in low light for too long. The foliage of that plant will revert and what will remain will be a Tradescantia zebrina var. discolor.

The phyllotaxis of the leaves on a stem has various patterns. The leaves can be alternate or whorled.
Furthermore divided to other types.

distichous/distichate: reference to the arrangement of the leaves on the stem, distichous leaves mean they are arranged in two vertical rows on opposite sides of an axis^[23].

form/f. (forma/plural formae in Latin): In botanical nomenclature, forma is one of the "secondary" taxonomic ranks, below that of variety, which in turn is below that of species; it is an infraspecific taxon. Variety differs from form/forma in that a variety implies predictable inheritable traits where form/forma traits occur sporadically within a population. Example: Tradescantia cerinthoides f. pilosa.

Gibasis: genus in the Commelinaceae family with - currently - 13 accepted species^[18]. Etymology: Latin gibbus (bulging, protuberant, swollen) + ancient Greek βάσις (basis) reference to the gibbous base of sepals.

glabrate: somewhat glabrous (smooth). Reference to the leaves.

glabrous: glabrous (smooth). Reference to the leaves.

hybrid: hybrid plants are usually sterile and propagated only through cuttings or tissue culture (TC), not by seed. An example of this might be the Tradescantia ‘Bermudensis’ (also known as Tradescantia 'Hawaiian Dwarf') which is a dwarf cultivar originating from the Tradescantia spathacea plant.

International Code of Nomenclature for algae, fungi, and plants (IAPT): The International Code of Nomenclature for algae, fungi, and plants (formerly known acronym was ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "traditionally treated as algae, fungi, or plants". Visit the IAPT website.

International Code of Nomenclature for Cultivated Plants (ICNCP): The International Code of Nomenclature for Cultivated Plants (ICNCP), also known as the Cultivated Plant Code, is a guide to the rules and regulations for naming cultigens, plants whose origin or selection is primarily due to intentional human activity. Every unique cultivar has a unique name within its denomination class (which is almost always the genus). Names of cultivars are regulated by the International Code of Nomenclature for Cultivated Plants, and may be registered with an International Cultivar Registration Authority (ICRA). Visit the ICNCP website.

International Cultivar Registration Authority (ICRA): An International Cultivation Registration Authority (ICRA) is an organization responsible for ensuring that the name of plant cultivars and cultivar groups are defined and not duplicated. Visit the ICRA website.

laekensis: synonym for Tradescantia fluminensis^[1]. Sometimes it is used as part of the name when describing the variegated Tradescantia mundula, but the species name laekensis is strictly a synonym of Tradescantia fluminensis.

lanceolate leaf, shaped like a lanced tip

lanceolate: reference to the shape of the whole leaf, being long, wider in the middle, shaped like a lanced tip.

lineatus, -a, -um: (botany) Marked longitudinally with depressed parallel lines. See also in the beginning of the page, further and more detailed definition when describing the specific color of this variegated pattern, such as: albolineata, aureolineatus etc.

nana: indicating a dwarf variety/cultivar/hybrid. Example: Tradescantia spathacea var. nana.

ovate leaf: oval, egg-shaped, wider near the petiole

ovate: reference to the shape of the whole leaf, having an oval, egg-shape, with a tapering point and the widest portion near the petiole. There are also variations to this. Like ovate-lanceolate, combining the two, which is more pointing to the tip of the leaf, but having a wide base near the petiole.

pendula: synonym for Tradescantia zebrina var. zebrina^[5]. See also: Tradescantia zebrina : varieties, cultivars, hybrids.

petiolate/petiolated: leaves that attached to stems with petioles are called petiolate leaves.

PGRs (Plant Growth Regulators): chemicals that are affecting the growth habit of plants: the growth hormone auxin. When a plant is treated with PGRs their foliage appears to be compact and with small leaves, but when the chemicals wear off after some weeks, the seemingly dwarf plant will start growing normally again, with large leaves and a non compact growth. Other PGRs are also altering the colors (making a plant look more purple, more vibrant etc.). Plants in the Commelinaceae family that were treated with PGRs are the: Tradescantia 'Hijau Baru', Tradescantia 'Nanouk', Tradescantia 'Purple Passion', Tradescantia zebrina 'Red Gem' (not the true 'Red Gem'), Tradescantia zebrina 'Red Juwel', Tradescantia zebrina 'Juwel Red', Tradescantia zebrina 'Pink Joy', Tradescantia zebrina 'Purple Joy'.

pilosulus, -a, -um: loosely pilose, somewhat hairy, diminutive of pilosus. Example: Tradescantia ambigua var. pilosula.

pilosus, -a, -um: covered with soft, distinct hairs, pilose, pilosus. Example: Tradescantia cerinthoides f. pilosa.

purpureus, -a, -um: from latin purpŭrĕus meaning purple, dark red. In the Commelinaceae family this taxon name describes the: Tradescantia pallida var. purpurea, the purple variety of the old known Tradescantia pallida (which is green).

recurvifolius, -a, -um: from the latin words rĕcurvus (recurved, bent back on itself) + folius (leaved). Refers to wavy edged leaves. Example: Tradescantia boliviana.

Rhoeo: very old synonym for the genus Tradescantia. It was used even before another old synonym (Setcreasea). We are talking about 3 centuries ago, and in some occasions it's still mentioned today^[6].

sessile/sessility: in botany, sessility (meaning "sitting", used in the sense of "resting on the surface") is a characteristic of plant parts (such as flowers and leaves) that have no stalk^[22].

Setcreasea: old synonym for the genus Tradescantia^[7]. Despite that this old genus name was described in the 19th century (200 hundred years ago)^[8], unfortunately it's still in use today occasionally, from some nurseries/vendors.

sport: in botany, a sport or bud sport, traditionally called lusus^[26] is a part of a plant that shows morphological differences from the rest of the plant. Sports may differ by foliage shape or color, flowers, fruit, or branch structure. The cause is generally thought to be a chance genetic mutation^[27].

Sports with desirable characteristics are often propagated vegetatively to form new cultivars that retain the characteristics of the new morphology^[28]. Such selections are often prone to "reversion", meaning that part or all of the plant reverts to its original form.

Image 1: shows the long stipe of a Helicteres flower. Image 2: shows the remains of the same plant, as each flower forms a fruit. Image 3: shows an orchid's stipe, with pollinia. Image 4: shows the stipe of a Laminaria hyperborea (Brown alga).

stipe: in botany, a stipe is a stalk that supports some other structure. The precise meaning is different depending on which taxonomic group is being described. In flowering plants, the term is often used in reference to a stalk that sometimes supports a flower's ovary. In orchids, the stipe or caudicle is the stalk-like support of the pollinia. It is a non-viscid band or strap connecting the pollinia with the viscidium (the viscid part of the rostellum or beak).

stipitate: possessing a stalk.

stipule: botany meaning with image example

stipule: A basal appendage of a typical leaf of a flowering plant, usually appearing paired beside the petiole although sometimes absent or highly modified.

striatus, -a, -um: it means striped, usually used to describe the (variegated) striped foliage. The term striatus is used in botany, the equivalent in zoology is vittatus. See also: albostriatus, aureostriatus mentioned in the beginning of this page.

sp. or sp. aff.: species affinis (commonly abbreviated as: sp. aff. or sp. or aff. or affin. ) is taxonomic terminology in zoology and botany. In open nomenclature it indicates that available material or evidence suggests that the proposed species is related to, has an affinity to, but is not identical to, the species with the binomial name it comes after. The Latin word affinis can be translated as "closely related to", or "akin to". Examples: Gibasis sp. 'Jose Puig'; Murdannia sp. 'Bright Star'.

subsp.: The term subspecies (ssp. in zoology) in general was consider less valid in botany. It was vastly circulated by European botanists in 1805 but in other places of the world it was considered invalid for botany, at the 19th century. The literature since then demonstrated a conservative usage of the term^[13]. Instead the terms forma and varietas were used. Nowadays we see the term subsp. more often in use in botany, therefore it should be defined. The terms “subspecies” and “variety” are used to designate the first and second divisions of a species. A “subspecies” is a grouping within a species used to describe geographically isolated variants, a category above “variety”, and is indicated by the abbreviation “subsp.” in the scientific name. A “variety” consists of more or less recognizable entities within species that are not genetically isolated from each other, below the level of subspecies, and are indicated by the abbreviation “var.” in the scientific name^[14].

tenella: it means soft / delicate / tender. Etymology: <Latin tĕnĕr ^{[24, 25]}. Example: Tradescantia tenella (synonym: Tradescantia fluminensis var. tenella).

Tradescantia Purple Heart: Purple Heart is the common name for Tradescantia pallida var. purpurea. Why var. purpurea and not 'Purpurea'? Because Tradescantia pallida var. purpurea grows wild as an introduced species to various parts all over the world^[21] and what has been introduced in those parts of the world is the purple one (the purpurea), thus not the old wild Tradescantia pallida which is green, not purple.

Tradescantia Purple Queen: Purple Queen is another common name for Tradescantia pallida var. purpurea.

Tradescantia quadricolor 'Rainbow Hill': everything in this plant name is utterly wrong. The way that the quadricolor is written it means that it's a taxon, but there's no taxon like: Tradescantia quadricolor. And the cultivar name 'Rainbow Hill' is fabricated as well. The actual name for that plant is: Tradescantia mundula 'Variegata'. And it doesn't even consisted of four colors (quadricolor means four colors). In the Commelinaceae family only two zebrina cultivars are consisted of four colors. These are the: Tradescantia zebrina 'Quadricolor' and a newer cultivar: Tradescantia zebrina 'Danny Lee'.

Tradescantia Tricolor: that is an insufficient name that some people use when they are referring to the Tradescantia mundula 'Variegata'. It's insufficient because tricolor just means three colors. There are also other Tradescantia cultivars out there with three colors. It brings confusion, especially to those new hobbyists that are now beginning to learn more about these plants.

Tripogandra: genus in the Commelinaceae family officially treated as a synonymous genus of Callisia^[15]. Yet some botanists with expertise in Commelinaceae (Marco O.O Pellegrini) do not accept this^[16]. Generally speaking, the genera of Commelinaceae have been divided among various groups by different authors. No general consensus has been reached and all schemes are unsatisfactory to some extent. As Robert E. Woodson stated: "the Commelinaceae always have been difficult subjects for herbarium study because of their deliquescent flowers (means that they tend to liquify). It is not easy to understand, therefore, why previous systematics of the family focused almost their whole attention upon floral structure in the delimitations of subfamilies, tribes, and genera"^[17]. Etymology: ancient Greek τρι tri (three) + ancient Greek πώγων pógon (beard) + ancient Greek ἀνδρός andrós (male).

tubercle: (1) A small rounded wart-like protuberance of the roots of some leguminous plants; the lip of certain orchids, cacti. (2) Bearing tubercles or warty protuberances, such as when identifying the upper leaf structure of some Commelinaceae plants (Tradescantia zebrina 'Danny Lee').

umbel: a flat-topped or rounded flower-cluster (inflorescence) in which the individual flower stalks arise from the same point, the youngest flowers being at the centre.

umbelliform: having the shape of an umbel.

varietas/var. (Latin; variety in english): Most Commelinaceae plants are easily crossed to each other and from that crossing new varieties may appear. According to the ICN botanical nomenclature, a naturally occuring variety is denoted with the denomination var. whilst the taxon name is written with the first letter of the genus capitalized and the rest with small letters. Plus it is written in italics except the var. denomination. Example: Tradescantia zebrina var. flocculosa. The terms “subspecies” and “variety” are used to designate the first and second divisions of a species. A “subspecies” is a grouping within a species used to describe geographically isolated variants, a category above “variety”, and is indicated by the abbreviation “subsp.” in the scientific name. A “variety” consists of more or less recognizable entities within species that are not genetically isolated from each other, below the level of subspecies, and are indicated by the abbreviation “var.” in the scientific name^[14].

villous: long and soft hairs (shaggy) - not matted^[20].

vittatus, -a, -um: it is used in zoology, the equivalent in botany is striatus.

zygomorphic flowers, monosymmetry, bilateral symmetry in Commelinaceae

Two plants from the Commelinaceae family with zygomorphic flowers, aka: bilateral symmetry.
Left: Aneilema aequinoctiale | Right: Commelina communis 'Aureostriata'.

zygomorphic (flowers): part of the Floral symmetry in botany. Zygomorphic etymology: yoke shaped, bilateral – from ancient Greek ζυγόν (zygon, yoke) and μορφή (morphe, shape) flowers can be divided by only a single plane into two mirror-image halves, much like a yoke or a person's face. Examples are orchids and the flowers of most members of the Lamiales (e.g., Scrophulariaceae and Gesneriaceae). Some authors prefer the term monosymmetry or bilateral symmetry. The asymmetry allows pollen to be deposited in specific locations on pollinating insects and this specificity can result in evolution of new species. In the Commelinaceae family plants with zygomorphic flowers are the Aneilema aequinoctiale and Commelina communis, among others.

Globally and within individual networks, zygomorphic flowers are a minority. Plants with zygomorphic flowers have smaller number of visitor species compared to those with actinomorphic flowers. Sub-networks of plants with zygomorphic flowers share greater connectance, greater asymmetry and lower coextinction robustness for both the plants and the visitor species. Plant taxa with zygomorphic flowers can have a greater risk of extinction due to pollinator decline.

References

1. POWO: Tradescantia fluminensis synonyms.

2. Online Latin Dictionary: albus.

3. POWO: Tradescantia cerinthoides synonyms.

4. POWO: Callisia soconuscensis.

5. POWO: search term: Tradescantia pendula.

6: IPNI: Rhoeo.

7. POWO: genus Setcreasea.

8. IPNI: genus Setcreasea.

9. POWO: genus Cyanotis, accepted species

10. Εικονογραφημένον Βοτανικόν - Φυτολογικόν Λεξικόν: Τόμος Δ΄, σελ. 2035

11. hbw.com: cyanotis / cyanotos