Striga todgarhica C.S. Purohit is reinstated in this paper. It used to be treated as a synonym of Striga angustifolia (D.Don) C.J. Saldanha but morphological characters of Calyx and Corolla support the reinstatement. These two species, together with S. asiatica make up a small group that is distributed in sandy-gravel desert area and have similar morphological characters. A key is provided to distinguish between them, and there is discussed and also recently describe species S. khordhae synonymized under S. angustifolia var. masuria.

The genus Striga was first recognized and validly published by Loureiro 1790 belonging to the family Orobanchaceae. The genus comprises about 42 species with the highest diversity in Tropical Africa (Jayanthi et al., 2014) where 28 taxa have been recorded of which 22 are endemic (Mohamed et al., 2001, Fischer et al. 2011). The genus is represented by approximately 11 species and 3 infra-species (Jeeva et al., 2012; Omalsree et al. 2015; Mao & Dash, 2020; Purohit 2021; Devi & Kumar, 2024). Six taxa so far reported from Rajasthan (Blatter & Hallberg, 1918; Bhandari, 1978; Shetty & Singh 1991; Kumar & Purohit, 2015; Purohit et al., 2020; Purohit, 2020a & b, 2021; Purohit et al., 2023; Purohit & Meena 2025).).

Reinstating Striga todgarhica C.S. Purohit

Striga todgarhica C.S. Purohit is endemic species of Rajasthan was originally described by C.S. Purohit from gravel area of Uperli Bhabhan, Pali, Rajasthan (Purohit, 2021) and housed in BSJO (Herbarium, Botanical Survey of India, Arid Zone Regional Centre, Jodhpur, Rajasthan). Due to type specimens available for examined, Arigela et al., (2024) reduce it to a synonym of Striga angustifolia (D.Don) Saldanha based on climatic and ecological factors and without any herbarium collection from type locality or any other locality.

During the field survey of different parts of Aravalli hills, Indian desert, Mount Abu, Katchh, various sanctuary of Rajasthan and collected the plant with flower & fruit. After carefully examined the type specimens and newly collected specimens of both species, author found that calyx and corolla to be significantly different. According to Hepper (1963) characters of diagnostic value in separating species include number of ribs in the calyx, indumentum, relative sizes of calyx and of corolla tubes, size of the bract subtending each flower, and flower color. Number of ribs in calyx is important identification characters in genus Striga and on the basis of this character classified all species under genus Striga (Berner et al., 1997). Temperature is an important factor affecting the distribution of Striga, as prolonged exposure to high temperatures and humid conditions is required to break seed dormancy in Striga (Ejeta and Gressel, 2007).

The calyx of S. todgarhica have narrow triangular and 13 ribs (Fig. 1A to 1E) while the calyx of S. angustifolia have linear and 15 ribs (Fig. 2A to 2E). In S. todgarhica one calyx rib terminating the tip of each lobe and others in the sinus (Fig. 1D & 1E) while S. angustifolia all three calyx rib terminating the tip of each lobe (Fig. 2-4). Corolla tube of S. todgarhica is up to 2 cm long, tube apically strongly curved; Upper lip 2-partite and lower lip tri to tetra-partite (Fig. 1A & 1B) while the corolla tube of S. angustifolia is 0.8-1.5 cm long, tube abruptly incurved at or above the middle, upper lip 2-partite and lower lip outside in bud, tri-partite (Fig. 3A & 3B; Fig. 4B & 4E). Study of herbarium sheets of Striga angustifolia in BSJO collected by various scientists of this office (Fig. 2 & 5) in different places and found same characters as observed above. Considering these significant differences, the name Striga todgarhica should be reinstated and characters of the species amended.

Taxonomic treatment

Striga todgarhica C.S. Purohit in J. New Biol. Repor. 10(2): 89-94. 2021.

Type: INDIA. Rajasthan, Todgarh-Raoli Wildlife Sanctuary, Jojawar Range, Uperli Babhan, 460m, (25 46.306' N; 73 56.897' E), 12 November 2017, C.S.Purohit 33306A, (Holo BSJO!); C.S.Purohit 33306B (Iso BSJO!).

Annual, erect herb, 10-25 cm tall, entirely hirsute. Stem erect, branched ribbed, hispidly hairy. Leaves green, linear to narrowly lanceolate, with subacute apex, alternate, sessile, 2-4 × 0.2-0.4 cm, densely hairy on dorsal side, flowers in lax, leafy terminal spikes. Bracts similar to leaf in shape and size, densely hairy; Bracteole 2, equal, linear, densely hairy on both side, 6-8 mm long. Calyx 6-8 mm long; calyx lobes 5, narrow triangular, hispid, calyx lobe half the length of calyx tube [lobe 2-3 mm long; tube 5-6 mm long]; calyx 13-ribbed, densely hispid along ribs, one calyx rib terminating the tip of each lobe and others in the sinus. Corolla white, salverform, tube 1.5-2 cm, apically strongly curved, lower lip tri-tetra partite, outside in budding; upper lip bilobed, 2.2-2.6 × 2.2-2.4 mm. Stamen 4, attached to distal end of the tube, just below the throat. Ovary 1.5-2 mm long, glabrous; style long upto 4-5 mm long, glabrous, brown colour at the tip. Capsule ovoid, 8-10 mm long, enveloped in persistent calyx. (Fig. 1)

Flowering & Fruiting: October - December.

Distribution: Endemic, India, Rajasthan, Todgarh-Raoli wildlife sanctuary.

Note: This species is strictly parasitic on the grass roots of Sorghum halepense (L.) Pers. belonging to family Poaceae. It grows on transition area of gravel and sandy habitat in associated with Aerva javanica (Burm.f.) Juss. ex Schult., Cordia sinensis Lam., Bergia ammannioides Roxb. ex Roth., Butea monosperma (Lam.) Taub., Calotropis procera (Aiton) Dryand., Commelina difusa Burm.f., Eragrostis amabilis (L.) Wight & Arn., Ipomoea nil (L.) Roth, Lindenbergia indica Vatke, Prosopis juliflora (Sw.) DC., Senna siamea (Lam.) H.S.Irwin & Barneby, Sorghum halepense (L.) Pers. and Trichosanthes tricuspidata Lour.

Key to the Striga todgarhica and morphologically similar congens

1a. Calyx 5-ribbed               2

1b. Calyx 10-15 ribbed               3

2a. Leaves normal, linear, green S. densiflora

2b. Leaves reduced to scales, purple S. gesnerioides

3a. Three calyx-ribs terminating the tip of each lobe, Calyx 15-ribbed S. angustifolia

3b. One calyx-rib terminating the tip of each lobe and others in sinus, Calyx 10-13 ribs 4

4a. Leaves smooth or villous; Calyx 10-ribbed, hispidulous along ribs, calyx lobe linear, as long as calyx tube; petals lower lip tripartite, yellow, white or red; S. asiatica

4b. Leaves densely hairy on dorsal side; Calyx 13-ribbed, densely hispid along ribs, calyx lobe narrow triangular, half the length of calyx tube; petals lower lip tri - tetra partite, white; S. todgarhica

Table 1: Distinguished characters between Striga todgarhica, S. angustifolia & S. asiatica.

Similar species

Striga asiatica (L.) Kuntze - Linnaeus first described this species as Buchnera asiatica based on material from the Comoros Islands near Madagascar. Loureiro separated Striga from Buchnera in 1790 and applied the name Striga lutea to yellow-flowered specimens collected in India. Many other names were subsequently applied to different variants in different regions, including Striga hirsuta by Bentham in 1846. Saldanha (1963) expressed doubts whether Linnaeus' original name was valid and proposed that it should be abandoned in favour of Striga lutea Lour. However, Hepper (1974) confirmed that the original name was valid and the combination Striga asiatica (L.) Kuntze is now generally accepted. The species shows great variability in stature, branching, hairiness, flower colour and host preference (Fig. 6A to 6E), and different forms may occur in the same region. Striga asiatica has close relationship with S. todgarhica and S. angustifolia. The diagnostic characteristics of the three species are shown in Table 1.

Specimen examined during study:

Striga todgarhica C.S. Purohit: Rajasthan: Todgarh-Raoli Wildlife Sanctuary, Jojawar Range, Uperli Babhan, 25 46.306' N; 73 56.897' E, 460m, 12.11.2017, C.S. Purohit 33306A, 33306B;

Striga asiatica (L.) Kuntze: Gujarat: Near nani Singhloti, Narmada, 08.09.2017, 20 36'00.4", 73 15'28.2", 125 m, Vinod Maina 35098; Near nani Singhloti, Narmada, 08.09.2016, 21 39'01.1", 73 37'49.1", 211 m, S.L. Meena 30600; Near Singhloti checkpost, Narmada, 29.08.2013, 21 39'54.2", 73 40'75.9", 277 m, S.L. Meena 27676;

Striga angustifolia (D.Don) Saldanha: Rajasthan: Dabla, Jaisalmer, 02.10.2017, C.S. Purohit 33609; Aasan, Bijaguda, Todgarh- Raoli, 03.09.2018, 25 57.1'17", 74 07.9'38", 442 m, C.S. Purohit 33562; Plantation near hampi, Along Desuri-Phulad Road, Pali, 24.08.1975, 335 m, B.V. Shetty 1867; On the way to Rajmahal R.F. Deoli, Tonk, 11.09.1974, 330 m, B.V. Shetty 1215; Sunda hill, Rajpura, Jalore, 15.09.1979, 340 m, B.L. Vyas 6863; Near Bhadrajun along Jodhpur- Jalor road, Jalore, 23.09.1979, 250 m, B.L. Vyas 7345; Barli, Jodhpur, 07.10.1976, 375 m, A.N. Singh 3119; CAZRI afforestation area, Beriganga compt. I, Jodhpur, 04.10.1972, 165 m, B.V. Shetty 165; Bhaduwala, Ganganagar, 08.10.1977, 122 m, G.P. Roy 4951; Parah village, Bhilwara, 22.09.1978, A.N. Singh 6498; Stream in Naga R.F., Siwana Barmer, 17.10.1975, 385 m, B.V. Shetty 2233; Near Forest Route house, Kusalgarh, Banswara, 24.08.1976, 850 m, V. Singh 3031; Lasara village, Banswara, 14.10.1976, 600 m, V. Singh 3620; Bhuja ki Dhani, on the way to Dipas, Sikar, 20.09.1992, P.J. Parmar 10531. Gujarat: Umrat, Navsari, 31.10.2015,  21 02'79.8", 72 44'90.0", 2.3m., Vinod Miana 31759; Palsava-Village, Kachchh, 06.10.2004, 250 m., R.P. Pandey 19902; NSWS-near Halapur, Kachchh, 14.10.2002, 60m., R.P. Pandey 13933; Taranga hills, Kheralu, Mehsana, 28.09.2003, P.J. Parmar 12934; Narayan sarovar, Haman khudi, Kutchh, 27.09.2000, V. Singh 15940; Jessore wildlife sanctuary, Banaskantha, 07.09.2004, 290m., S.L. Meena 20796; Aaji dam, Rajkot, 23.08.2008, 150m., P.M. Padhye 23757; Nalsarovar Birds Sanctuary, Amdavad, 29.08.2005, 65m., S.L. Meena 21283; Pond near village sapar, Jamnagar, 15.02.2004, 50 ft., P.M. Padhye 18895; Dhovadri- Bhatiya, Jamnagar, 14.10.2003, 3000 ft., P.M. Padhye 18678; Near Shawlaji, Sabarkantha, 24.09.2005, P.J. Parmar 22784; Velavadar Blackbuck National Park, Bhavnagar, 12.08.2009, S.L. Meena 24362; Jessore wildlife sanctuary, Banaskantha, 21.08.2003, 450m., S.L. Meena 18124; Goraj, Amdavad, 30.08.2005, 65m., S.L. Meena 21400; Umrat, Navsari, 31.10.2015,  21 02'79.8", 72 44'90.0", 2.3m., Vinod Maina 31750; Gichand forest, Narmada, 01.09.2013, 21 43'38.4", 73 40'95.2", 343m., S.L. Meena 27752; Junaraj Forest, Narmada, 02.09.2014, 21 46'24.1", 73 38'18.1", 430m., S.L. Meena 30274; Bansda national park, Navsari, 07.09.2017, 20 46.3'74.7", 73 29.1'12.1", 127m., Vinod Maina 35042.

Synonymizing Striga khordae Sanjeet Kumar & Devi with Striga angustifolia (D.Don) Saldanha var. masuria (Buch.-Ham. ex Benth.) Omalsree & V.K. Sreenivas

Described characters of a recently published new species S. khordae by Devi & Kumar (2024) i.e. smaller calyx, calyx lobes unequal to subequal, length one third as long as tube, each lobe of lower lip of corolla lobe is divided up to the half-length, longer capsule and seed surface irregularly pitted are developed in climate variation and all these characters reported in S. angustifolia var. masuria by Omalsree & Sreenivas (2018). According to Hepper (1963) characters of diagnostic value in separating species include number of ribs in the calyx and its clear-cut show the calyx having 15 ribs in S. khordae (photos of published paper) as well as S. angustifolia var. masuria and it revealed that S. angustifolia var. masuria shows characters i.e. pubescent nature of the plant, white corolla lobes, 15-ribbed calyx lobes, length of the plant, the loosely arranged flowers and closely positioned ribs on calyx lobes. Based on study of protologues and type specimens, author found that all the taxonomic characters of S. khordae (Devi & Kumar, 2024) are very similar and fall within the circumscription of S. angustifolia and treated as synonym of it.

Taxonomic treatment

Striga angustifolia (D. Don) Saldanha var. masuria (Buch.-Ham. ex Benth.) Omalsree & V.K. Sreenivas, J.O.T.T. 10(9): 12294-12297. 2018.

= Striga masuria (Buch.-Ham. ex Benth.) Benth. Compan. Bot. Mag. 1: 364. 1836.

= Buchnera masuria Buch.-Ham. ex Benth. in Scroph. Ind.: 41. 1835.

= Buchnera wallichii Benth. in N.Wallich, Numer. List: n. 3876 (1831), nom. nud.

Lectotype: Nepal, Morang hills, 28.vii.1810, Francis (Buchanan) Hamilton, 1419 (E barcode: E00273651); Isolectotypes, K000899664, K001117506.

Syntypes: Myanmar, Prome, 09.x.1826, N. Wallich, 1161 (K K001117505, K000899663, E00273649).

= Striga khordae Sanjeet Kumar & Devi, J. Biodivers. Conservation 8(2): 23-27. 2024.

Holotype: India, Odisha, Khordha district, Godibari, 20 32' 25.71" N, 85 74' 39.92" E, c 48 m, 3 August 2020, S. Kumar & R.S. Devi 30 (Herbarium of Ambika Prasad Research Foundation).

Erect annual, chlorophyllous herbs, 15-68 cm tall. Stem densely hispid, quadrangular, green, branched from middle to apex or unbranched. Leaves opposite at base, alternate towards apex, sessile, 10-40 × 1-4 mm, linear-lanceolate, acute at apex, cuneate at base, hairy on both surfaces especially on mid-rib; margins entire or ciliate with strigose hairs; mid-rib prominent. Inflorescence a raceme, terminal or from axils of upper leaves, 15-45 cm long. Rachis angular, strigose hairy. Flowers zygomorphic, sessile or subsessile, hypogynous, lax, alternate, 22-34 per inflorescence. Bract 1, 2.6-2.9 mm long, linear-lanceolate, hairy. Bracteoles 2, 1.8-2.1 mm long, linear-lanceolate, hairy. Calyx 6-8 mm, tubular, 15-ribbed; ribs distantly arranged and ending up to the teeth; lobes 5, 2-2.8 mm long, linear-lanceolate, hairy, green or with a brownish tinge. Corolla bilabiate; tube 8.8-9.8 mm long, prominently curved above the middle, greenish; lobes creamy-white, 3.8-4.4 mm long, broadly obovate, hiary; throat 4-4.2 mm long, hairy. Stamens 4, included, didynamous; filaments 1.5-3.2 mm long, attached to the distal end of the corolla tube; anthers 1-celled. Ovary superior, 2-celled, 2-2.2 mm long, oblong to ellipsoid, glabrous; ovules many, axile; style 4.8 mm long, white, brown at apex, glabrous; stigma brown. Fruit 5.5 mm long, ellipsoid, beaked. Seeds numerous, 0.3-0.4 mm long, ellipsoid, irregularly pitted, glabrous.

Fig. 1. Striga todgarhica C.S. Purohit: (A & B) - Whole plant with flowering; (C) - Calyx with nerves; (D) - Calyx ventral view showing 13 ribs; (E) Calyx dorsal view showing 13 ribs with one nerves reach on tip.

Fig. 2. Striga angustifolia (D.Don) Saldanha: (A) - Herbarium-collected from Katchchh, Gujarat; (B & C) - Calyx with ribs; (D & E) - Calyx close-up showing three ribs reach up to tip of calyx.

Fig. 3. Striga angustifolia (D.Don) Saldanha flower & bud shows three nerves in each calyx rich up to tip: (A & B) - Plant at Todgarh-Raoli wildlife sanctuary, Rajasthan; (C & D) - Plant at Mount Abu wildlife sanctuary, Rajasthan; (E) - Plant at Pali, Rajasthan.

Fig. 4. Striga angustifolia (D.Don) Saldanha flower & bud shows three nerves in each calyx rich up to tip: (A & B) - Plant at Desert National Park, Jaisalmer, Rajasthan; (C & D) - Plant at, Machiya Biological Park, Jodhpur, Rajasthan; (E & F) - Plant at Viratra Mata, Barmer, Rajasthan.

Fig. 5. Striga angustifolia (D.Don) Saldanha: (A) - Herbarium sheets, collected from Jalore, Rajasthan; (B) - Herbarium sheets, collected from Barmer, Rajasthan; (C) - Herbarium sheets, collected from Bhilwara, Rajasthan; (D) - Herbarium sheets, collected from Pali, Rajasthan; (E) - Herbarium sheets, collected from Tonk, Rajasthan.

Fig. 6. Striga asiatica (L.) Kuntze: (A) - Herbarium sheets, collected from Bansda National Park, Gujarat; (B & C) - Calyx close-up showing one ribs reach up to tip of calyx; (D) - Buds; (E) - Close-up of flower with leaf.