Heliotropium pakistanicum sp. Nov. (Boraginaceae) from Pakistan

Heliotropium pakistanicum sp. Nov. (Boraginaceae) identificada no Paquistão

ABSTRACT:

Heliotropium pakistanicum

Shaheen sp. nov., has been described as new species to science. This taxon has been collected from Thal Desert, Punjab province, Pakistan. This species is closely associated with H. cabulicum Bunge. However, It differs from H. cabulicum in its leaf shape, inflorescence and glabrous corolla tube and bulbose base hairs. Taxonomic details of Heliotropium pakistanicum have been provided in this article.

Keywords:
pakistani flora weed; Punjab; Thal Desert

RESUMO:

Heliotropium pakistanicum

Shaheen sp. nov. é descrita como uma nova espécie para a ciência. Este táxon foi coletado no deserto de Thal, província de Punjab, Paquistão. Esta espécie está intimamente associada à H. cabulicum Bunge. No entanto, difere de H. cabulicum no que diz respeito à forma da folha, inflorescência e tubo da corola glabro e pelos de base bulbosa. Detalhes taxonômicos de Heliotropium pakistanicum foram fornecidos neste artigo.

Palavras-chave:
planta daninha da flora Paquistanesa; Punjab; deserto de Thal

INTRODUCTION

Boraginaceae (Synonym: Lennoaceae, Hydrophyllaceae) family comprises about 135 genera and 2,600 species mostly distributed in tropical, subtropical and temperate regions of the world (Retief and Van Wyk, 2008). This family is characterized by a scorpioid cymose inflorescence (Buys and Hilger, 2003), a gynobasic style, and a two-part ovary that breaks into four nutlets. This circumscription is equivalent to, and has in the past been referred to as, Boraginaceae s.s. or Boraginoideae (Small, 1903; Diane et al. 2002; Weigend et al. 2010). This broader circumscription has included four taxa treated as either subfamilies (Boraginoideae, Cordioideae, Ehretioideae, and Heliotropioideae) or families that are characterized by a scorpioid cyme and two-parted gynoecium (style position and fruit type vary) (Lawrence, 1937; Cronquist, 1981; Al-Shehbaz, 1991; Takhtadzhian, 1997).

From Pakistan, 32 genera and 135 species are so far identified fror Boraginaceae family. Heliotropium (add authority) is a large and complex genus with about 270-300 species occurring in temperate and tropical regions of both the hemispheres in the world (Ali and Nasir 1989; Nasir, 1989; Forther, 1998). Heliotropium is known as the largest genus of the family for the Flora of Pakistan (Ali and Nasir, 1989). General characteristics of genus Heliotropium are annual or perennial, prostrate to erect herbs or undershrubs with usually vinous to scabrid indumentum, rarely glabrous. Leaves alternate, entire. Inflorescence usually of terminal or axillary scorpiod cyme. Flowers small, white, bracteate or not. Calyx usually 5-partite into linear or lanceolate lobes, persistent. Corolla 5-lobed, tubular to infundibuliform, hairy on the outside and sometimes variously so within; lobes ± erect or inflexed, obtuse to linear, with dentations or lobed between them or not. Stamens 5, free, included and attached to the corolla tube; anthers elongated, subsessile, sometimes apiculate. Ovary 4-locular or incompletely 2-locular. Style erect. Stigma ± conical or elongated. Stigmatic disc usury present. Fruit comprising of 2-4 nutlets.

In this paper, a new species Heliotropium pakistanicum Shaheen has been described for science from the Thal Desert, Punjab Province of Pakistan. It was collected in 2010-2015 during undertaking floristic surveys the area in question and this appears to be the first new species.

MATERIALS AND METHODS

The Thal Desert was explored for the floristic enumeration during 2010-2015 for collecting plant species. The collected specimens were pressed, dried and mounted on standard herbarium sheets along with liquid collection in Copenhagen mixture (Moore, 2010). Both the dried and liquid specimens were properly examined by using stereoscope (WILD M5) with a camera lucida attachment. Using the relevant characteristics, each specimen was identified with the Flora of Pakistan (Boraginaceae) and other relevant floras (add references other flora you have consulted).

RESULTS AND DISCUSSION

Key to species

This is key of only those species, which were collected and identified from Thal Desert:

1a. Calyx shallowly 5-lobed, completely enclosing the fruit................................................................................. H. supinum

1b. Calyx 5-partite; not completely enclosing the fruit:.......................................................................................... 2a

2a. Plants glabrous................................................................................................................................................. H. curassavicum

2b. Plants vinous to scabrid:................................................................................................................................... 3a

3a. Stigmas 2, linear-recurved, exserted................................................................................................................. H. ophioglossum

3b. Stigma solitary, minutely 2-fid or capitate, included........................................................................................ 4a

4a. Stigma capitate, entire...................................................................................................................................... H. rariflorum

4b. Stigma conical, entire or not:............................................................................................................................ 5a

5a. Flowers bracteates: ............................................................................................................................................. 6a

6a. Effect semi-shrubby herbs; leaves linear, 25-50 mm long................................................................................... H. zeylanicum

6b. Prostrate to decumbent herbs; leaves linear lanceolate to elliptic: ..................................................................... 7a

7a. Inflorescence compact, 20-40 mm long; leaves lanceolate to elliptic; flowers sessile......................................... H. marifolium

7b. Inflorescence lax, 20-100 mm long; leaves linear-lanceolate...................................................................... H. strigosum

5b. Flowers ebracteate: ................................................................................................................................... 8b

8a. Corolla lobes caudate-acuminate....................................................................................................................... H. subulatum

8b. Corolla lobes obtuse to ovate or caudate: .................................................................................................. 9a

9a. Corolla hairy within: ......................................................................................................................................... 10a

10a. Hairs within corolla in two distinct zones. ................................................................................................ H. baluchistanicum

10b. Hairs not present in zones:. ..................................................................................................................... 9b

9b. Corolla glabrous within: ............................................................................................................................ 11a

11a. Corolla 4-8 mm long:. ............................................................................................................................... 12b

12a. Corolla lobes linear, inflexed. Stigma 1.5-1.8 mm long.............................................................................. H. gillianum

12b. Corolla lobes ± ovate, obtuse. Stigma 0.7-0.8 mm long: ............................................................................ 11b

11b. Corolla 2-3 mm long:. ............................................................................................................................... 13a

13a. Hairs-arising from a swollen base: ............................................................................................................ 14a

14a. Leaves ovate-lanceolate to lanceolate, margin entire to ± undulate; inflorescence up to 9 flowered;

corolla uniformly hairy within......................................................................................................................... H. cabulicum

14b. Leaves lanceolate, margin deeply undulate; inflorescence up to 15-flowered; corolla glabrous within ...... H. pakistanicum

13b. Hairs without a swollen base.................................................................................................................... H. biannulatum

15a. Leaves elliptic to obovate, 10-25 mm long; flowers close set; anthers 0.5-0.6 mm long, narrow,

attached c. 0.5 mm from corolla base; stigma 0.4 mm long........................................................................ H. ovalifolium

15b. Leaves ovate, 7-10 mm long; flowers distantly placed; anthers c. 1 mm long, ± ovate, attached

c. 0.9 mm from corolla base; stigma 1 mm long ........................................................................................... H. remotiflorum

16a. Plants annual:. ......................................................................................................................................... 17a

17a. Corolla lobes sublinear, inflexed.............................................................................................................. H. alii

17b. Corolla lobes ovate to oblong, obtuse: ..................................................................................................... 18a

18a. Plants greyish-white. Flowers uniseriate. Calyx deciduous at length......................................................... H. calcareum

18b. Plants green to greenish-grey. Flowers biseriate. Calyx persistent at length.............................................. H. europaeum

16b. Plants perennial: ...................................................................................................................................... 19a

19a. Corolla lobes ovate to oblong, obtuse: ..................................................................................................... 20a

20a. Leaves ovate to oblong-ovate; anthers oblong, 1.8-2 mm long.................................................................. H. ulophyllum

20b. Leaves lanceolate to linear-lanceolate; anthers narrow ovate, 0.8-1 mm long:........................................... 19b

19b. Corolla lobes sublinear, inflexed: ............................................................................................................. 21a

21a. Plants erect to suberect, stems up to 5 mm thick at base; leaf margin crisp-undulate; nutlet margin

not-winged...................................................................................................................................................... H. crispum

21b. Plants decumbent to procumbent; stems up to 15 mm thick at base; leaf margin revolute or

indistinctly undulate; nutlet margin winged..................................................................................................... H. bacciferum

22a. Anthers connectives not produced ............................................................................................................ H. dasycarpum

22b. Anthers connectives produced: ................................................................................................................. 23a

23a. Sinuses of corolla lobes without dentitions or lobes; anthers 1.0 mm long................................................. H. aucheri

23b. Sinuses of corolla lobes with dentitions or lobes....................................................................................... H. lamondiae

Taxonomic details

Heliotropium pakistanicum Shaheen sp. nov. ( Figure 1 )

Figure 1
Heliotropium pakistanicum sp. nov.

Perennial semi-erect herb about 60 cm tall. Stem much branched at the base, woody below, herbaceous above, circular, green, densely villous; internodes ca. 1.5-2.5 cm. Leaves alternate, spirally arranged, succulent, ca. 1-3 x 0.3-0.5 cm, linear-lanceolate or oblong; apex broadly acute; base cuneate, margin dentate-undulate; midrib prominent, diffusely strigose; hairs 1-celled, bulbose based, 1mm long; petiole 1 mm, densely strigose. Inflorescence ca. 0.5-2.5 cm long, forked, 6-15 flowered; peduncle ca.0.5-1.5 cm, circular, green, villous. Flowers sessile, complete, campanulate, creamy. Sepals ca. 4 x 3 mm, green, persistent; lobes 5, elliptic; apex obtuse; margin entire, densely villous. Petals lobes 5, yellow, ovate-oblong; apex obtuse; margin undulate, ca. 1-1.5 mm long, abaxially sparsely hairy; tube ca. 3 mm. Stamens 5, epipetalous, ca. 3 mm; anthers elliptic-lanceolate, base rounded, apex subacute; filaments small. Ovary globose, ca. 1 mm across; style filiform, ca. 2 mm; stigma 4-fid, conical, glabrous. Nutlets 4, whitish grey, hairy, depression on the inner side, ca. 3 mm across.

Etymology: Pakistan: Punjab, Thal Desert

Holotype: Pakistan, Punjab, Thal desert, 03-04-2010, Humaira Shaheen, Collector No (1886- PMAS-AAUR)

Other specimen examined: Pakistan, Punjab, Thal desert, 31-03-2013, Humaira Shaheen, Collector No (2605- PMAS-AAUR); Pakistan, Punjab, Thal desert, 16-08-2014, Humaira Shaheen, Collector No (3319 - PMAS-AAUR);Pakistan, Punjab, Thal desert, 02-04-2015, Humaira Shaheen, Collector No (4309 - PMAS-AAUR).

Flowering Period: April.

Collector Name: Humaira Shaheen

Distribution: Currently endemic to Thal desert, Punjab Pakistan.

Resemblance with other species (Affinities)

Heliotropium pakistanicum Shaheen sp. nov., has been described as new species to science. The species is closely associated with H. cabulicum Bunge as close sympatric relative which occurs in Baluchistan, Pakistan. It differs from H. cabulicum in its leaf shape, inflorescence and glabrous within the corolla tube, however resembles it in bulbose base hairs. This species is widely distributed in Thal Desert (Punjab). This species differs from H. cabulicum in floral as well as vegetative characters. This is a perennial, semi-erect herb up to 60 cm tall. Leaves distinctly lanceolate, deeply undulate, villous. Anthers elliptic, apex subacute, 3 mm across. Ovary globose, style filiform, ca. 2 mm. Nutlets whitish grey, hairy, depression on the inner side. (Shown in Table 1).

Table 1
Diagnostic characters of Heliotropium pakistanicum

Plant part	Character	Illustration
Habit	Semi-erect
Leaves shape	Lanceolate
Leaves margin, texture	Deeply undulate and Villous
Inflorescence	Forked
Corolla	Glabrous inner side (bulbose base hairs)
Anthers	Elliptic, subacute apex
Style	Filiform at tip
Ovary	Globose
Nutlets	Hairy, depression on inner side

Heliotropium pakistanicum much resemble to Heliotropium cabulicum but have following distinguish characters (Table 2).

Table 2
Heliotropium pakistanicum comparison with Heliotropium cabulicum

S. No.	Heliotropium pakistanicum	Heliotropium cabulicum
1	Semi-erect herb about 60 cm high	Erect up to 40 cm
2	Stem densely Villous hairy	Stem antrorsely hairy
3	Leaves succulent	Leaves not succulent
4	Diffusely strigose hairs at the midrib and densely strigose hairs at entire leave	Scabrid with short strigose Hairs on leaves
5	Leaves linear-lanceolate or oblong	Leaves ovate-lanceolate or lanceolate
6	Inflorescence fork shape	Inflorescence
7	Sessile flower	Pedicel from 2-5 mm long
	6-15 flowered in each fork	3-9-flowered in a inflorescence
8	Petels lobes ovate-oblong	Petels lobes lanceolate
9	Anther elliptic, apex subacute and sessile	Anther elongate and subsessile
10	Style filiform	Style multifurcated
11	Ovary ovate	Ovary compressed
12	Nutlets whitish grey, depression on the inner side	Nutlets glabrous, dark brown

This species is common in plan sandy area of Thal Desert (Punjab). This plant is not reported before any area of the world we reviewed different literature such as Flora of China, Flora of Pakistan, Flora of America etc. This description is also verified by different taxonomist in Pakistan and USA (University of California Davis).

ACKNOWLEDGMENTS

This research article is the part of my Ph.D. work, I highly grateful to Higher Education Commission (HEC) for the Ph.D. Indigenous scholarship. I am also thankful to Pakistan Science Foundation for providing project on Thal Desert, this project give financial support for conducting survey.

REFERENCES

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Publication Dates

• Publication in this collection
  13 June 2019
• Date of issue
  2019

History

• Received
  11 Feb 2017
• Accepted
  03 Mar 2017