Abutilon hirtum, (Lam.) Sweet

Nimbalkar, Varsha Vilasrao & Sardesai, Milind Madhav, 2025, The Genus Abutilon (Malvaceae: Malvoideae) in India: A Taxonomic Revision and Insights from Micromorphology of Seeds, Systematic Botany (Basel, Switzerland) 49 (4), pp. 708-742 : 717-718

5. ABUTILON HIRTUM (Lam.) Sweet in Hort. Brit. [Sweet] ed. 1, 53. 1826. Sida hirta Lam. In Encycl. 1: 7. 1783. Abutilon hirtum (Lam.) G. Don in Gen. Hist. 1: 503. 1831. Isonym. A. graveolens var. hirtum (Lam.) Mast. in Hook. f., Fl. Brit. India 1: 327. 1874. TYPE: INDIA. P. Sonnerat 2486 [lectotype designated here: G-DC G-00219621 [photo]! (https://www. ville-ge.ch/musinfo/bd/cjb/chg/adetail.

php?id=219234&lang=en)].

Sida graveolens Roxb. ex Horneum , in Hort. Beng. 50. 1814., nomen nudum. Abutilon graveolens (Roxb. ex Hornem.) Wight & Arn. in Catal. Pl. 13. 1833. nom. illeg.

Abutilon heterotrichum Hochst. ex Mattei, Boll. Reale Orto Bot. Palermo n. s., 1: 90 (1915). A. hirtum var. heterotrichum (Hochst. ex mattei) Cufod., Bull. Jard. Bot. Etat Bruxelles 29 (suppl.): 536 (1959). Type : ETHIOPIA, W. Schimper 2306 [lectotype designated here: K-000240389 (http:// specimens.kew.org/herbarium/ K000240389 ) isolectotypes: P P00389232 [photo]!; BR BR0000008403742 ; GOET GOET007704 ].

Shrubs, 2–3 m tall. Stem brown; young stem covered with numerous stellate hairs, sticky glandular hairs and long simple hairs. Leaf lamina 5–15 3 2–10 cm, ovate to orbicular, stellate and glandular pubescent, apex acuminate, margin sharply dentate–coarsely serrate, subentire, 5–7-nerved. Petioles 3–10 cm long, stellate pubescent with glandular and long simple hairs. Stipules 5–6 mm long. Flowers axillary, solitary; flowering pedicel ca. 2 cm long, articulated 4–5 mm below the flower; fruiting pedicel 3–4 cm long, articulated 5–6 mm below the fruit. Calyx campanulate, 1.5–1.7 cm across, lobes ovate, 6–7 mm long, acute or acuminate at apex, may or may not exceed apex of schizocarp. Corolla 2.5–3 cm across, yellow, mostly with a dark reddish colored patch at the center, sometimes plain yellow; petals 5–10 3 4–8 mm, broadly obovate, truncate or unequal at apex, emarginate, glandular hairs on abaxial side, reflexed in fully bloomed flower. Staminal column 7–9 mm; base conical, reddish or plane yellow, stellate pubescent; tube 2–3 mm long, glabrous; filaments 3–5 mm, glabrous. Ovary 4 3 3 mm, globose, 22–25 carpellary, stigma capitate. Schizocarps 1.5–2 3 1–1.5 cm, globular, slightly indented and truncate at apex, mericarps 22 (may reduce by abortion)–25. Mericarps 1–1.3 3 0.5 cm, reniform, base rounded, upper part rounded with mucro or minute awn, dorsally curved, 2–3-seeded. Seeds 1.8–2 3 1.8–2 mm, reniform, warted, surface pubescent, hilum densely pubescent with stellate hairs all over placental attachment, brownish. Figures 6A–E , 7A–G .

Distribution and Habitat —The species is native to tropical Asia, Africa, and Australia; introduced and naturalized in Mexico, Central, South and North America, and West Indies. In India, it occurs in many states ( Fig. 8 ). Common throughout the study area, grows on roadsides, wastelands, and sometimes on hill slopes.

Etymology —Epithet hirtum denotes the hairy appearance of a plant.

Phenology —Flowering begins from July to February, fruiting from September to March. Flowers usually open after 2 or 3 PM.

Notes —Plants of this species are generally distinguished by a dark reddish patch at the center of the corolla. The patch may appear faint or sometimes the corolla looks plain yellow.

An infraspecific taxon A. hirtum var. heterotrichum (Hochst. ex mattei) Cufod. is enumerated in some Indian floristic analyses ( Paul and Nayar 1988; Paul 1993) by using leaf margin as a character (sharply dentate vs. coarsely serrate) to discriminate from the main variety. However, the character of the leaf margin varies according to the age of the leaf and environmental conditions. Moreover, the protologue of A. heterotrichum (basionym of A. hirtum var. heterotrichum ) distinguished it from other congeneric taxa by the feature of smaller and closer carpels. The character seems indeterminate because, in all the populations and herbarium specimens studied for A. hirtum , adjacent carpels are always observed to be closely arranged. Hence, ‘var. heterotrichum’ is not treated as a distinct taxon here.

The name A. hirtum (Lam.) Sweet (5 Sida hirta Lam. ) is typified here with the specimen from G (G-DC, G-00219621), collected by Sonnerat from “de l’ Inde ” ( India) which exhibits characters given in the protologue. A search for the original material in G-DC was insisted by Lamarck’ s (1783) collaboration with De Candolle for the work ( Stafleu and Cowan 1979).

For lectotypification of the name A. heterotrichum Hochst ex Mattei , a specimen from Schimper’ s collection (2306) from Ethiopia housed at K is selected. Other specimens from the

collection placed at various herbaria are selected as isolectotypes.

Representative Specimens— India. — ANDHRA PRADESH: Kadapa Dt., Balapalle, 20 Jan 1958, SKW7567 ( BLAT) ; Cuddapah, 22 Jan 1958, SKW 7767, 7708, ( BLAT). Nellore Dt., Shivdurg, 15 Aug 1957, SKW 6760 ( BLAT). Warangal Dt., Narasampet, 280m, 25 Nov 1960, K. M. Sebastine 11593 ( MH) . — GUJARAT: Jamnagar Dt., Harshad Road, 11 Feb 2004, P. M. Padhye 18807 ( BSJO) ; Nageshwar, 11 Feb 2004, P. M. Padhye 21801 ( BSJO) . — KARNATAKA: Bagalkot Dt., Kulali, May 1917, s.c. 18359 ( BLAT). Shimoga Dt., Lingadahalli, 18 Nov 1991, A. K. Pradeep 44961 ( CALI) . — KERALA: Idukki Dt., Marayur, 14 Feb 2015, VVN 541 ( BAMU, SPPU). —MAHAR- ASHRA: Ahmednagar Dt., Khandgaon, 17 Dec 1984, Rajendra Shinde 124 ( BLAT). Beed dt., Parli, 16 Oct 2014, VVN 507 ( BAMU, SPPU). Nagpur Dt., North Ambazari road, 15 Nov 1959, U. Pirashi 242 ( BLAT). Sindhudurg Dt., Burdi, Kolgaon, Savantwadi, 8 Mar 1982, S. M. Almeida SMA4343 ( BLAT) . — RAJASTHAN: Banswara Dt., Banswara city, roadside, 24 Sep 2015, VVN 556 , ( BAMU). Panchmahal Dt., Pavagadh, 25 Sep 2015, VVN 560 ( BAMU, SPPU) . — TAMIL NADU: Chennai Dt., Vandalur, 11 Feb 2015, VVN 531 ( BAMU, SPPU) ; Maraimalai Nagar, 11 Feb 2015, VVN 535 ( BAMU, SPPU). Coimbatore Dt., Maruthmalai, 26 Nov 1990, A. K. Pradeep 5237 ( CALI) ; Pollachi, 24 Dec 1991, A. K. Pradeep 5244 ( CALI) ; Coimbatore to Maruthmalai road, 13 Feb 2015, VVN 539 ( BAMU, SPPU) ; Aliyar, 13 Feb 2015, VVN 540 ( BAMU, SPPU). Ramanathapuram Dt., Manamadurai, 125m, 25 Jun 1978, N. C. Nair 57469 ( MH). Salem Dt., Chennai to Salem Road , 12 Feb 2015, VVN 536 ( BAMU, SPPU). Tindivanam Dt. , Tindivanam city, 15 Feb 2015, VVN 542 ( BAMU, SPPU). Tiruchirapalli Dt. , Tiruchirapalli city, 16 Sep 2016, VVN 575 ( BAMU, SPPU) . — TELANGANA: Krishna rivar bank, near Nagarjunsagar dam, 24 Dec 2017, VVN 600 ( BAMU, SPPU) . — WEST BENGAL: Howrah Dt., Panchala, 10 Nov 1964, Bennet 1050 ( CAL) .

Figures

FIG. 6. Habit and morphology of A. hirtum (A–E) and A. indicum (F–J). A, F. Habit and flower. B, G. Fruit. C, H. Dehiscing fruit. D, I. Mericarp. E, J. Seed. (A, B by Gajanan Tambde).

FIG. 7. Line drawing illustration of A. hirtum (A–G, drawn from VVN 507) and A. indicum (H–N, drawn from VVN 582). A, H. Leafy twig with flower and fruits. B, I. Flower. C, J. Staminal column. D, K. Gynoecium. E, L. Fruit. F, M. Mericarp. G, N. Seed.

FIG. 8. Distribution of A. hirtum, A. indicum, A. neelgerrense var. fischeri, and A. neelgerrense var. neelgerrense in India.