Ourisia caespitosa, or creeping mountain foxglove, is a species of flowering plant in the family Plantaginaceae that is endemic to New Zealand. Joseph Dalton Hooker described O. caespitosa in 1853. Plants of this species of New Zealand foxglove are perennial herbs that are mostly glabrous (hairless), with trilobed or irregularly notched leaves that are tightly packed along a creeping stem. It is listed as Not Threatened.

Ourisia caespitosa
Ourisia caespitosa floweirng plants observed on the South Island, New Zealand

Not Threatened (NZ TCS)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Lamiales
Family: Plantaginaceae
Genus: Ourisia
Species:
O. caespitosa
Binomial name
Ourisia caespitosa
Synonyms

Ourisia caespitosa var. gracilis Hook.f.[2]

Taxonomy edit

Ourisia caespitosa Hook.f. is in the plant family Plantaginaceae.[3][4] Joseph Dalton Hooker described O. caespitosa in Volume II of his Flora Antarctica series, Flora Novae-Zelandiae 1853.[5][6] It is known as creeping mountain foxglove.[4][3]

The type material was collected by William Colenso in the Ruahine Range of the North Island, and by David Lyall in Milford Sound, South Island, New Zealand.[7][5] The lectotype was designated by Heidi Meudt and is housed at the herbarium of the Royal Botanical Gardens, Kew.[7][5] Although O. caespitosa var. gracilis was described by Joseph Hooker in 1867, it was considered to be a synonym of O. caespitosa in the latest taxonomic treatment.[2][5]

Ourisia caespitosa can be distinguished from all other New Zealand species of Ourisia by its mostly glabrous aspect, trilobed or irregularly notched leaves that are tightly packed along the creeping stem.[5]

Ourisia caespitosa is morphologically most similar to another New Zealand species, O. glandulosa. It can be distinguished from that species by its hairless leaves (vs. leaves sparsely to densely hairy on the upper side) and the three lines of yellow hairs inside the corolla tube (vs. glabrous inside the tube).[5]

Description edit

 
Habit of Ourisia caespitosa
 
Close up of flower of Ourisia caespitosa, showing three lines of hairs inside corolla tube
 
Close up of glabrous leaves of Ourisia caespitosa

Ourisia caespitosa plants are perennial herbs. The stems are creeping, many-branched, and densely packed with repent, opposite leaves. Leaf petioles are 0.8–9.4 mm long. Leaf blades are 1.9–9.4 mm long by 1.1–6.3 mm wide (length: width ratio 1.2–2.0: 1), usually narrowly to broadly ovate or obovate, widest below or above the middle, with a rounded apex, cuneate base, and trilobed or with up to 4 irregular notches or teeth. Leaves mostly glabrous, and on the lower surface densely punctate. Inflorescences are erect, glabrous racemes up to 125 mm long, with 1–3 flowering nodes and up to 6 total flowers per raceme. Each flowering node 1–2 flowers and 2 sessile, clasping bracts that are usually narrowly to broadly ovate or obovate. The lowest bracts are similar to the leaves, 3.1–8.2 mm long and 1.4–6.3 mm wide, and become smaller toward the tip of the raceme. The flowers are borne on a glabrous pedicel up to 32 mm long. The calyx is 4.3–7.4 mm long, irregular, with 3 lobes divided to about one-quarter the length of the calyx and 2 divided to near the base, and usually glabrous. The corolla is 11.3–19.3 mm long (including the 3.9–9.7 mm long corolla tube), white, bilabiate, tubular-funnelform, glabrous on the outside, with 3 lines of yellow hairs on the inside. The corolla lobes are 3.5–10.9 mm long, spreading, and obovate to obcordate. There are 4 stamens up to 8.3 mm long which are didynamous, with two long exserted stamens and 2 short stamens included inside the corolla; a short staminode up to 4 mm long is also present. The style is 4.4–7.6 mm long, exserted, with a capitate stigma. The ovary is 1.8–4.0 mm long and glabrous. Fruits are capsules 4.2–6.8 mm long and 2.6–4.8 mm wide with loculicidal dehiscence and pedicels up to 21.0 mm long. There are about 160 tiny seeds in each capsule, 0.6–1.0 mm long and 0.4–0.6 mm wide, rectangular, linear oblong or narrowly oblong with a two-layered, reticulate seed coat.[5][8]

 
Fruiting plants of Ourisia caespitosa

Ourisia caespitosa flowers from October to March and fruits from December to April.[5] O. caespitosa was one of eight widespread species whose populations at higher elevations flower 3–5 weeks earlier than those at lower elevations in Cupola Basin, Nelson Lakes National Park.[9]

The chromosome number of Ourisia caespitosa is 2n=48.[10]

Distribution and habitat edit

 
Ourisia caespitosa in alpine, rocky habitat

Ourisia caespitosa is a New Zealand foxglove that is endemic to the North, South and Stewart Islands of New Zealand.[3] It is widespread and common in most high-elevation areas.[5]

In the North Island it is found in the Gisborne, Volcanic Plateau and Southern North Island regions, whereas on the South Island it widespread throughout all regions. On Stewart Island, it is known from Mt Anglem | Hananui.[5]

It grows in herbfields, grasslands and scrub above the bush line, often in damp places, on shingle, scree, rocks, crevices, outcrops and cliffs from 540 to 2000 m m above sea level.[5]

Phylogeny edit

Individuals of O. caespitosa were included in phylogenetic analyses of all species of the genus Ourisia using standard DNA sequencing markers (two nuclear ribosomal DNA markers and two chloroplast DNA regions) and morphological data.[11][12] In all analyses, the sampled individuals belonged to the highly supported New Zealand lineage, but in the nuclear ribosomal DNA dataset and combined analyses, only three of the four sampled individuals of O. caespitosa were monophyletic.[11] Relationships between New Zealand species were nevertheless not well resolved.[11][12]

In another phylogenetic study using amplified fragment length polymorphisms (AFLPs), all 49 sampled individuals formed a clade or a significant cluster the analyses, and there were three distinct geographical lineages within this cluster comprising individuals from 1) central North Island, 2) southern South Island and remaining North Island individuals, and 3) Otago, South Island.[13]

Biology edit

Ourisia caespitosa was one of several New Zealand alpine flowering plants used in field experiments to show that flower color influences insect visitation in alpine New Zealand.[14]

O. caespitosa is one of many alpine species from New Zealand with axillary buds (flower primordia) that form in autumn, but it is also one of a handful of species whos axillary buds are obviously enlarged.[15]

Seeds of O. caespitosa contain ecdysteroids at 4.5 mg per gram.[16]

Conservation status edit

Ourisia caespitosa is listed as Not Threatened in the most recent assessment (2017–2018) of the New Zealand Threatened Classification for plants.[17]

References edit

  1. ^ Hooker, Joseph Dalton; Hooker, Joseph Dalton; Fitch, W. H.; Brothers, Reeve (1853). The botany of the Antarctic voyage of H.M. discovery ships Erebus and Terror in the Years 1839-1843 :under the command of Captain Sir James Clark Ross. Vol. v.2:pt.1(1853). London: Reeve Brothers.
  2. ^ a b Hooker, Joseph Dalton (1867). Handbook of the New Zealand flora : a systematic description of the native plants of New Zealand and the Chatham, Kermadec's, Lord Auckland's, and Macquarrie's islands.
  3. ^ a b c "Ourisia caespitosa". New Zealand Plant Conservation Network. Retrieved 7 April 2024.
  4. ^ a b "Flora of New Zealand | Taxon Profile | Ourisia caespitosa". www.nzflora.info. Retrieved 7 April 2024.
  5. ^ a b c d e f g h i j k Meudt, Heidi (24 April 2006). "Monograph of Ourisia (Plantaginaceae)". Systematic Botany Monographs. 77: 1–188.
  6. ^ Hooker, Joseph Dalton; Hooker, Joseph Dalton; Fitch, W. H.; Brothers, Reeve (1853). The botany of the Antarctic voyage of H.M. discovery ships Erebus and Terror in the Years 1839-1843 :under the command of Captain Sir James Clark Ross. Vol. v.2:pt.1(1853). London: Reeve Brothers.
  7. ^ a b "Lectotype of Ourisia caespitosa Hook. f. [family PLANTAGINACEAE] on JSTOR". plants.jstor.org. Retrieved 7 April 2024.
  8. ^ Webb, Colin; Simpson, Margaret Jane Annand (1 January 2001). Seeds of New Zealand Gymnosperms and Dicotyledons. Caxton Press, Manuka Press.
  9. ^ Clarke, C. M. H. (1 June 1968). "Flowering periods of alpine plants at Cupola Basin, Nelson, New Zealand". New Zealand Journal of Botany. 6 (2): 205–220. Bibcode:1968NZJB....6..205C. doi:10.1080/0028825X.1968.10429058.
  10. ^ Hair, J. B.; Arroyo, M. T. Kalin; Beuzeberg, E. J. (1 July 1984). "Contributions to a chromosome atlas of the New Zealand flora — 28 Ourisia (Scrophulariaceae)". New Zealand Journal of Botany. 22 (3): 357–359. Bibcode:1984NZJB...22..357H. doi:10.1080/0028825X.1984.10425267.
  11. ^ a b c Meudt, Heidi; Simpson, Beryl Brintnall (18 April 2006). "The biogeography of the austral, subalpine genus Ourisia (Plantaginaceae) based on molecular phylogenetic evidence: South American origin and dispersal to New Zealand and Tasmania". Biological Journal of the Linnean Society. 87 (4): 479–513. doi:10.1111/J.1095-8312.2006.00584.X.
  12. ^ a b Meudt, Heidi; Simpson, Beryl Brintnall (1 October 2007). "Phylogenetic analysis of morphological characters in Ourisia (Plantaginaceae): Taxonomic and evolutionary implications". Annals of the Missouri Botanical Garden. 94 (3): 554–570. doi:10.3417/0026-6493(2007)94[554:PAOMCI]2.0.CO;2.
  13. ^ Meudt, Heidi; Lockhart, Peter; Bryant, David M. (20 May 2009). "Species delimitation and phylogeny of a New Zealand plant species radiation". BMC Evolutionary Biology. 9 (1): 111. Bibcode:2009BMCEE...9..111M. doi:10.1186/1471-2148-9-111. PMC 2700801. PMID 19457251.
  14. ^ Campbell, Diane R.; Bischoff, Mascha; Lord, Janice; Robertson, Alastair (1 September 2010). "Flower color influences insect visitation in alpine New Zealand". Ecology. 91 (9): 2638–2649. Bibcode:2010Ecol...91.2638C. doi:10.1890/09-0941.1. PMID 20957958.
  15. ^ Mark, A. F. (1 March 1970). "Floral initiation and development in New Zealand alpine plants". New Zealand Journal of Botany. 8 (1): 67–75. doi:10.1080/0028825X.1970.10428606.
  16. ^ Sarker, Satyajit D.; Savchenko, Tamara; Whiting, Pensri; Lafont, René; Dinan, Laurence N. (16 February 2012). "The genus Ourisia (Scrophulariaceae): a potential source of phytoecdysteroids". Biochemical Systematics and Ecology. 24 (7–8): 803–804. doi:10.1016/S0305-1978(96)00083-X.
  17. ^ Lange, Peter J. de; Rolfe, Jeremy R.; Barkla, John W.; Courtney, Shannel P.; Champion, Paul D.; Perrie, Leon R.; Beadel, Sarah M.; Ford, Kerry A.; Breitwieser, Ilse; Schönberger, Ines; Hindmarsh-Walls, Rowan (May 2018). "Conservation status of New Zealand indigenous vascular plants, 2017" (PDF). New Zealand Threat Classification Series. 22: 1–86. OCLC 1041649797.

External links edit