| Catamixis | |
|---|---|
 | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Subfamily: | Pertyoideae |
| Tribe: | Pertyeae |
| Genus: | Catamixis Thomson[1] |
| Species: | C. baccharoides |
| Binomial name | |
| Catamixis baccharoides Thomson | |
| Synonyms[1] | |
Baccharis oliganthaDC. ex Thomson | |
Catamixis is agenus assigned to the familyAsteraceae, with only one known species,Catamixis baccharoides, a low to medium height shrub. It is native to a very small area of western Nepal and northern India in the Himalayas. It has spoon-shaped, leathery leaves with rounded teeth, set alternately along straight, shyly branching stems. They carry many flower heads about 1 cm (0.4 in) long, with a few creamy white florets, sometimes with a hint of violet, incorymbs at the end of the branches. Flowers and fruits can be found between March and May.[2] Its vernacular name in Hindi isविषपत्री (vishpatri) orविश्पत्र (vishpatra).[3]
Catamixis baccharoides is a shrub 0.75–1.75 m (2 ft 6 in – 5 ft 9 in) high, with straight, shyly branching stems, which are circular in cross-section, initially covered in silky hairs pressed to the surface, but later becoming hairless, carryingalternately set leaves close together, which leave distinct marks after being shed. The leaves are leathery and hairless, up to 8 cm (3.1 in) long and 3.5 cm (1.4 in) wide, spoon-shaped, the base tapering into the stalk, while the margin is somewhat wavy, with distanced rounded teeth particularly in the upper half. The flower heads are set in corymbs at the end of the branches or in the leaf axils. Each flower head consists of aninvolucre, 5–6 mm (0.20–0.24 in) high, with several whorls of lanceolate bracts narrowing into the tip, with papery edges, and contains mostly five, sometimes four or six,hermaphrodite creamy whiteligulate florets 3.7 cm (1.5 in) long, ending in five shallow, but irregular lobes. Each of the five individualanthers per floret has two spurs at its base, giving them an arrow-shaped foot. Like in all Asteraceae, the pinkish anthers are fused into a tube through which the style grows, while picking up the pollen that is released at the inside of the tube. The shaft of the style only has few hairs at its base. When ripe, the style opens into two branches about 0.5 mm (0.02 in) long with shortstigmatic papillae at the dorsal side. There are no bracts on the common base of the florets. The indehiscent one-seeded fruits (calledcypselas) are 2 mm (0.08 in) long, covered in velvety hairs, and are adorned by ten longitudinal ribs. Thesepals which are changed to barbed 8 mm (0.31 in) long hairs calledpappus are white in color. The pollen istricolpate and has some small spines of less than 1 μm (3.9×10−5 in) high.[2][4][5]
The flower heads ofCatamixis contain florets with ligulate corollas only, a trait shared with theLactuceae, but also withFitchia,Hyaloseris,Dinoseris andGlossarion.[6]
Catamixis baccharoides was described byThomas Thomson in 1867, who thought it was most closely related toLeucomeris, a genus that is now assigned to the subfamilyWunderlichioideae, tribeHyalideae. It has been difficult to establish the relationships ofCatamixis with other asterids, since no substantial analysis of its genetic material has been published so far.[when?] Because it shares the combination ofligulate florets, spurred anthers, and involucres that consist of severalwhorls of overlapping bracts, the species was initially assigned to the tribe Mutisieaesensu lato, but genetic analysis has since shown that this grouping constitutes a basalevolutionary grade, which has been consequentlydivided into nine subfamilies.[7] However, further characters ofCatamixis are shared with different of these subfamilies or the subdivisions they include, but always elements of the unique character combinations of these subfamilies are lacking inCatamixis. More recently,Catamixis was assumed to be associated with the tribePertyeae.Catamixis lacks a deletion of 17base pairs close to one of thechloroplast NADH dehydrogenase genes, that is a common character for members of the subfamiliesGymnarrhenoideae,Cichorioideae,Corymbioideae andAsteroideae.Catamixis,Pertya,Myripnois and two of theAinsliaea-species share a deletion of 145 base pairs not found in any lineage except Pertyoideae. Apoint mutation in thematurase K gene is shared with the generaAinsliaea andPertya, which belong to the Pertyoideae. This makes it very likely thatCatamixis should be included in the Pertyoideae, but does not fully resolve the position within that subfamily.[8]
The nameCatamixis is a contraction of the Greek wordsκατά (kata) andμιξη (mixi), meaning “mixed affinity”, which refers to the combination of characters that makes it difficult to assign it based on morphology within the Asteraceae.[8]
This is a narrow range, endemic, monotypic genus distributed in lower Shiwalik belt of Western Himalaya from an altitude range of 500–1,000 m (1,600–3,300 ft). The species is reported from few localities in India from Haryana, Himachal Pradesh, Uttarakhand and Uttar Pradesh and one from West Nepal. The species is habitat specific and grows on exposed, dry, sandstone or calcareous rocky cliffs of lower Shiwalik belt.[9]
Since the species is threatened, a number of efforts were carried out for its conservation under ex-situ conservation. This habitat-specific species is also propagated and cultivated in the botanical garden of Botanical Survey of India, Dehradun in an artificially created rocky mound[9] and is also planted in the experimental garden of Forest Research Institute, Dehradun.[10]