Holmgrenanthe

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Holmgrenanthe
Holmgrenanthe petrophila.jpg
Status TNC G1.svg
Critically Imperiled  (NatureServe) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Lamiales
Family: Plantaginaceae
Tribe: Antirrhineae
Genus: Holmgrenanthe
Elisens
Species:
H. petrophila
Binomial name
Holmgrenanthe petrophila
Synonyms [2]
  • Maurandya petrophilaCoville & C.V.Morton
  • Asarina petrophila(Coville & C.V. Morton) Pennell
  • Maurandella petrophila(Coville & C.V. Morton) Rothm.

Holmgrenanthe petrophila (rocklady, formerly Maurandya petrophila) is a rare perennial desert plant in the plantain family (Plantaginaceae), and the sole species of the genus Holmgrenanthe. It forms low mats of branched stems growing from a woody base. The leaves have small spines along their edges. The solitary yellow flowers are tubular with five free lobes at the end, the upper two pointing backwards, the lower three projecting forwards. The species is known only from about ten locations, most in the Titus Canyon and the adjacent Fall Canyon, all within the Californian section of Death Valley National Park. It grows in limestone crevices on the canyon walls, often on the north face.

Contents

Description

Holmgrenanthe petrophila is an herbaceous perennial with fibrous roots. It is low growing with slender, branched stems arising from a woody base; as it often grows on vertical faces, the stems tend to hang down. Close relatives climb using twining leaf stalks (petioles), but H. petrophila has straight petioles, 12–27 mm (0.5–1.1 in) long. The leaves are rounded or kidney shaped with small spines or bristles along the margins (spinulose) and at the apex. They are 12–35 mm (0.5–1.4 in) long by 14–27 mm (0.6–1.1 in) wide. [3]

In its native habitat, H. petrophila flowers and fruits in spring and early summer, between April and June. The solitary flowers are borne on very short stalks (peduncles), only 1–4 mm (0.04–0.16 in) long. The green sepals are narrow, pointed and not joined, forming an urn shape around the base of the flower. They are 9–13 mm (0.4–0.5 in) long by 2–3 mm (0.08–0.12 in) wide at the base. They have small spines along their margins, like the leaves. The five petals forming the corolla are joined at their bases to form a tube 20–24 mm (0.8–0.9 in) long. The free lobes at the end of the flower are 7–12 mm (0.3–0.5 in) long and differentiated into two upper lobes, curving backwards, and three lower lobes, pointing forwards. [3] The color of the corolla has been described as either sulfur yellow throughout [3] or white with a yellow throat. [4]

The style and stamens stay within the flower. The four stamens are of two lengths, the upper two with filaments 12–44 mm (0.5–1.7 in) long, the lower two with filaments 7–9 mm (0.3–0.4 in) long. There is also a fifth rudimentary sterile stamen. The ovary has a single chamber with an incomplete T-shaped septum. After fertilization, a globe shaped capsule forms containing tan colored seeds. [3]

Taxonomy

The genus Holmgrenanthe was established in 1985 by Wayne J. Elisens solely for the species H. petrophila, previously placed in Maurandya (including Maurandella). Elisens considered the species sufficiently different from other members of Maurandya to warrant a new genus. For example, it has short mat-forming stems, rather than long climbing or scrambling stems; the edges of the leaves and sepals are spiny; the ovary has a single chamber rather than two. The generic name honors Arthur H., Noel H., and Patricia K. Holmgren, described by Elisens as "dedicated botanists and students of the western flora." [3]

The genus is placed in the tribe Antirrhineae, originally part of the family Scrophulariaceae, [3] but now in the Plantaginaceae. [4] Within this tribe, Elisens defined the subtribe Maurandyinae for the five North American genera Holmgrenanthe, Lophospermum , Mabrya , Maurandya and Rhodochiton (the last of which he included in Lophospermum). [3]

Phylogeny

Lack of relevant information has led to Holmgrenanthe being excluded from the molecular phylogenetic studies confirming that Elisen's Maurandyinae together with Asarina and Cymbalaria form a monophyletic group (clade), [5] but analyses based on morphological characters suggest that Holmgrenanthe was the first diverging genus within the clade, retaining features of the earliest ancestor. The cladogram presented by Ghebrehiwet is shown below: [6]

Tribe Antirrhineae

Holmgrenanathe

Asarina – not in Maurandyinae sensu Elisens

Mabrya

Maurandya (including Maurandella)

Lophospermum (including Epixiphium)

Rhodochiton

rest of the tribe

Species

The sole species in the genus, Holmgrenanthe petrophila, [7] was first described in 1935 by Frederick Vernon Coville and Conrad Vernon Morton (as Maurandya petrophila). [8] They did not explain the origin of the specific epithet, [9] but petro- is derived from the Greek for rock and -phila from the Greek for beloved, [10] so that petrophila means "rock-loving". The plants described by Coville and Morton were growing in a north facing vertical limestone wall in Titus Canyon in Death Valley, California. [9] As noted above, the species was transferred to the new genus by Elisens in 1985. [3]

Distribution and habitat

After the species was first discovered in Titus Canyon, further plants were found in the adjacent Fall Canyon. It is known only from about ten locations, mostly in these two canyons, [11] all within the Californian section of Death Valley National Park. It grows in limestone crevices on the canyon walls, often on the north face, in areas dominated by creosote bush scrub. [4] [3] Elisens suggested that Holmgrenanthe petrophila might be a "paleoendemic", originally having a much larger range, but now confined to more sheltered and moister microhabitats in desert canyons as a consequence of a warming and drying trend 11,000–8,000 years ago. [3]

Conservation

As of July 2014, Holmgrenanthe petrophila is listed by the California Native Plant Society as "rare, threatened, or endangered in California and elsewhere". It is listed as critically endangered by the California State but is not listed at the federal level in the United States, nor in the IUCN Red List. [11]

Related Research Articles

<i>Rhodochiton</i> Genus of flowering plants

Rhodochiton is a genus of flowering plants within the family Plantaginaceae, native to southern Mexico and neighbouring Guatemala. They climb by means of twining leaf stalks. One of the three species, Rhodochiton atrosanguineus, the purple bell vine, is grown as an ornamental plant. All three species are sometimes included in Lophospermum.

<i>Lophospermum</i> Genus of flowering plants

Lophospermum is a genus of herbaceous perennial climbers or scramblers, native to mountainous regions of Mexico and Guatemala. Those that climb use twining leaf stalks. Their flowers are tubular, in shades of red, violet and purple, the larger flowers being pollinated by hummingbirds. Now placed in the greatly expanded family Plantaginaceae, the genus was traditionally placed in the Scrophulariaceae. The close relationship with some other genera, particularly Maurandya and Rhodochiton, has led to confusion over the names of some species.

<i>Asarina</i> Genus of flowering plants

Asarina is a flowering plant genus of only one species, Asarina procumbens Mill. the trailing snapdragon, which is native to France and Spain and introduced in Germany, Switzerland, Austria and Hungary. Originally placed in the Scrophulariaceae, the genus has more recently been moved to the Plantaginaceae. Species from North America formerly placed in the genus Asarina are now placed in Holmgrenanthe, Lophospermum, Mabrya and Maurandya, as well as Neogaerrhinum. Asarina is now regarded as exclusively an Old World genus.

<i>Maurandya</i> Genus of flowering plants

Maurandya is a genus of flowering plants in the family Plantaginaceae, native to Mexico and the south west United States. They sprawl or climb by means of twining leaf stalks. One of the four species, Maurandya barclayana, is widely cultivated as an ornamental plant.

<i>Lophospermum erubescens</i> Species of flowering plant

Lophospermum erubescens, known as Mexican twist or creeping gloxinia, is a climbing or sprawling herbaceous perennial plant, native to the Sierra Madre Oriental mountains of Mexico, where it is found along forest margins or canyon walls. It climbs by means of twining leaf stalks. Wild plants have pink and white tubular flowers, although other colours are found in cultivation. It has been cultivated as an ornamental plant since at least 1830. Although not frost-hardy, it will survive if its base and roots are protected from freezing in the winter. It has escaped from cultivation and become naturalized in tropical and subtropical areas of the world.

<i>Lophospermum scandens</i> Species of flowering plant

Lophospermum scandens is a scambling or climbing herbaceous perennial native to south central Mexico, with red-violet and white tubular flowers and toothed heart-shaped leaves. It grows at elevations between 1,400 and 2,400 m in dry habitats, including deciduous oak forests and recent lava flows. The long-tubed flowers are pollinated by hummingbirds. It has been used in gardens as an ornamental plant since the mid-19th century. Its roots require protection from frost in regions where this occurs in the winter. Hybrids of L. scandens are also grown.

<i>Mabrya</i> Genus of flowering plants

Mabrya is a genus of flowering plants in the plantain family, Plantaginaceae. It consists of herbaceous perennials with brittle upright or drooping stems, found in dry areas of Mexico and the southern United States.

<span class="mw-page-title-main">Antirrhineae</span> Tribe of flowering plants

The Antirrhineae are one of the 12 tribes of the family Plantaginaceae. It contains the toadflax relatives, such as snapdragons.

<i>Maurandya scandens</i> Species of flowering plant

Maurandya scandens, also known as trailing snapdragon and snapdragon vine, is a climbing herbaceous perennial native to Mexico, with snapdragon-like flowers and untoothed leaves. It is grown as an ornamental plant in many parts of the world, and has commonly escaped from cultivation to become naturalized. Other names for this plant include creeping snapdragon, vining snapdragon, creeping gloxinia and chickabiddy.

<i>Epixiphium</i> Species of flowering plant

Epixiphium wislizeni, commonly known as baloonbush, is a species of flowering plant in the plantain family, Plantaginaceae. It is the sole species in genus Epixiphium. It is a scrambling or climbing perennial subshrub native to Chihuahua state in northern Mexico and the south western United States where it grows in sand dunes. It has tubular flowers in shades of blue to violet and white and more-or-less triangular untoothed leaves.

<i>Maurandella</i> Species of flowering plant

Maurandella antirrhiniflora, known as roving sailor or climbing snapdragon, is a species of flowering plant in the family Plantaginaceae. It is the sole species in genus Maurandella. It is a scrambling or climbing herbaceous perennial subshrub native to Mexico, the southwestern United States, Cuba, and the Turks and Caicos Islands, where it grows in a variety of relatively dry subtropical habitats.

<i>Lophospermum purpusii</i> Species of flowering plant

Lophospermum purpusii is a scambling or climbing herbaceous perennial native to Mexico. It has tubular flowers, white at the base and red to violet elsewhere.

Rhodochiton hintonii is a climbing or sprawling herbaceous perennial native to the state of Guerrero in Mexico. It has dangling flowers, with a bell-shaped calyx and dark purple petals forming a tube. Unlike the better known Rhodochiton atrosanguineus, the petal tube is asymmetrical with two "lips".

Rhodochiton nubicola is a climbing or sprawling herbaceous perennial native to the state of Chiapas in Mexico and to Guatemala, where it grows in cloud forests at between 1,300 and 3,000 m. It has dangling flowers, with a bell-shaped calyx and dark purple petals forming a tube. Unlike the better known Rhodochiton atrosanguineus, the petal tube is asymmetrical with two "lips".

Lophospermum purpurascens is a climbing or scrambling herbaceous perennial native to Mexico, occurring in the states of Oaxaca, Veracruz and possibly Puebla. It has tubular flowers, white at the base and dark purple elsewhere. It was first described by Wayne J. Elisens in 1985. The epithet purpurascens means purplish or becoming purple.

Mabrya geniculata is a mat-forming herbaceous perennial native to the Mexican states of Sonora and Chihuahua. It has pale yellow tubular flowers. It was first described in 1894 by Benjamin L. Robinson and Merritt L. Fernald in the genus Maurandya and transferred to Mabrya by Wayne J. Elisens in 1985.

Mabrya flaviflora is a mat-forming herbaceous perennial native to a small area in Baja California Norte, Mexico. It has pale yellow tubular flowers. It was first described by Ivan M. Johnston in 1924 in the genus Maurandya and transferred to Mabrya by Wayne J. Elisens in 1985 as Mabrya geniculata subsp. flaviflora. It was restored to a full species within Mabrya by David A. Sutton in 1988. The epithet flaviflora means yellow-flowered.

Mabrya coccinea is a mat-forming herbaceous perennial native to the Mexican state of Coahuila. It has red tubular flowers. It was first described by Ivan M. Johnston in 1950 in the genus Maurandya and transferred to Mabrya by Wayne J. Elisens in 1985. The epithet coccinea means red.

Mabrya rosei is a mat-forming herbaceous perennial native to the Mexican states of Jalisco and Zacatecas. It has tubular flowers, whitish at the base and red to red-violet at the apex. It was first described by Philip A. Munz in 1926 in the genus Maurandya and transferred to Mabrya by Wayne J. Elisens in 1985. Munz did not explain the origin of the epithet rosei but listed the collector of the type specimen as Joseph Nelson Rose.

Mabrya erecta is an upright herbaceous perennial native to Mexico – the states of Chihuahua, Coahuila, Durango, Nuevo León and possibly México. Unlike other members of the genus Mabrya, it does not form mats. It has tubular flowers, whitish at the base and pink to red-violet at the apex. It was first described by William B. Hemsley in 1882 in the genus Maurandya and transferred to Mabrya by Wayne J. Elisens in 1985. The epithet erecta means erect or upright.

References

  1. "NatureServe Explorer 2.0".
  2. 1 2 "Holmgrenanthe petrophila (Coville & C.V.Morton) Elisens", Tropicos.org, Missouri Botanical Garden, retrieved 2014-07-20
  3. 1 2 3 4 5 6 7 8 9 10 Elisens, Wayne J. (1985), "Monograph of the Maurandyinae (Scrophulariaceae-Antirrhineae)", Systematic Botany Monographs, 5: 1–97, doi:10.2307/25027602, JSTOR   25027602
  4. 1 2 3 MacKay, Pam (2014), Mojave Desert Wildflowers (2nd ed.), Guildford, Connecticut: FalconGuides, p. 243, ISBN   978-0-7627-8033-4
  5. Vargas, Pablo; Valente, Luis M.; Blanco-Pastor, José Luis; Liberal, Isabel; Guzmán, Beatriz; Cano, Emilio; Forrest, Alan & Fernández-Mazuecos, Mario (2013), "Testing the biogeographical congruence of palaeofloras using molecular phylogenetics: snapdragons and the Madrean–Tethyan flora", Journal of Biogeography, 41 (5): 932–943, doi:10.1111/jbi.12253, S2CID   52840508
  6. Ghebrehiwet, Medhanie; Bremer, Birgitta & Thulin, Mats (2000), "Phylogeny of the tribe Antirrhineae (Scrophulariaceae) based on morphological and ndhF sequence data", Plant Systematics and Evolution, 220 (3–4): 223–239, Bibcode:2000PSyEv.220..223G, doi:10.1007/bf00985047, S2CID   36061550
  7. "Holmgrenanthe", The Plant List Version 1.1, retrieved 2014-07-12
  8. "IPNI Plant Name Query Results for Holmgrenanthe petrophila", The International Plant Names Index , retrieved 2014-07-19
  9. 1 2 Coville, Frederick V. & Morton, C.V. (1935), "A new species of Maurandia from Death Valley", Journal of the Washington Academy of Sciences, 25: 281–293, retrieved 2014-07-19
  10. Stearn, W.T. (2004), Botanical Latin (4th (p/b) ed.), Portland, Oregon: Timber Press, p. 269, ISBN   978-0-7153-1643-6
  11. 1 2 "Holmgrenanthe petrophila", Rare and Endangered Plant Inventory (online edition, v8-02), Californian Native Plant Society, 2014, retrieved 2014-07-19