Striga (Witchweed) - Photo Gallery of Species

S. angustifolia

1. Striga angustifolia seeds (left) and S. asiatica seeds (right). Human hair in middle. India. Photo by L. J. Musselman.

S. asiatica

1. Plant attached to maize, North Carolina, USA. Photo by L. J. Musselman.
2. Close-up of open flowers, North Carolina, USA. Photo by L. J. Musselman.
3. Yellow flower color form of the species.  Trang Insular Botanical Garden, Peninsular Thailand. Photo October 2005 by A. Fleischmann.
   
4. Close-up of flower buds, the stage where self-fertilization occurs (plants are autogamous, see Nickrent and Musselman, 1979, Brittonia 31:253-256). North Carolina, USA. Photo by L. J. Musselman.
5. Seedling attaching to maize root. SEM photo by L. J. Musselman.

S. aspera

1. Shoot with flowers. Africa. Photo by L. J. Musselman.
2. Close-up of flower. Africa. Photo by L. J. Musselman.

S. bilabiata

1. Several inflorescences. Africa. Photo by L. J. Musselman.
2. Inflorescence.  Zambia. Serenje District. Central Province. Kasanka National Park. Photo by J. Morawetz.

S. brachycalyx

1. Shoot with flowers (they should be more evenly pink than this scan shows). Africa. Photo by L. J. Musselman.
2. Flowering shoots in the field and with solid background. Open savanna woodland; near Grupe Game Camp. Ghana. From Virtual Field Herbarium, Department of Plant Sciences, Oxford. Photo P. Ekpe/NSBP.

S. densiflora

1. Comparison of S. densiflora (left) and S. angustifolia (right). Africa. Photo by L. J. Musselman.

S. elegans

1. Close-up of the brilliant red flowers. Africa. Photo by L. J. Musselman.
2. Another view of the flowers. South Africa. Photo by W. H. Hodge. Link goes to TROPICOS image library at MO.
3. Flowering shoot.   E Cape Trappes Valley, South Africa. Photo 7 March 2005 by C. Davidson. From FloraoftheWorld.org.

S. forbesii

1. Plants parasitizing sugar cane. Africa. Photo by L. J. Musselman.
2. Plant in flower. Zambia. Serenje District. Central Province. Kasanka National Park. Photo by J. Morawetz.

S. gesnerioides

1. Close-up of shoot with flowers. Photo by L. J. Musselman.
2. Excavated plants showing the bulbous primary haustoria. Makwa. Photo by L. J. Musselman.
3. Introduced plants parasitizing Indigofera hirsuta (hairy indigo, a legume) in Florida. Photo by L. J. Musselman.
4. Plants parasitizing cowpea, one of their favorite hosts. Africa. Photo by L. J. Musselman
5. Plants parasitizing Euphorbia. This plant was named Striga barthlottii by Fisher et al. (Willdenowia 41, 2011) but, according to Kamal I. Mohamed, its characters fall within the range of the very polymorphic species S. gesnerioides. Until we have molecular data to document that this taxon is distinct, it is best to consider it part of S. gesnerioides. Link goes to PhytoImages.

S. hermonthica

1. S. hermonthica on millet in Africa. The tiny plant (arrow) causes much damage to crops in Africa. Photo by L. J. Musselman.
2. S. hermonthica, Close-up of flowers - quite beautiful, despite being a nasty pathogen. Sudan. Photo by L. J. Musselman.
3. S. hermonthica. On maize in Africa. Photo by L. J. Musselman.
4. Scanning electron micrograph (SEM) of a Striga hermonthica seedling (P) parasitizing the root of its host (H), Zea mays. Hyaline body of the haustorium (HB). Bar = 0.1 mm. From Dörr, I. 1997. How Striga parasitizes its host: a TEM and SEM study. Annals of Botany 79:463-472. Used with permission.
5. Light micrograph of a longitudinal section through the region of the hyaline body (HB) of the haustorium (Ha) of Striga hermonthica and through the attached host root (H). The parasite cells have spread within the vessel (V) of the host. Xylem elements of the parasite have traversed the haustorium, fusing in the xylem disk (XD). Bar = 0.1 mm. From Dörr, I. 1997. How Striga parasitizes its host: a TEM and SEM study. Annals of Botany 79:463-472. Used with permission.
6. SEM of a longitudinally sectioned Striga hermonthica haustorium (Ha) penetrating a Zea host root (H). A pitted host vessel member has been invaded by several oscula (Os), each showing openings at their tips. Bar = 10 µm. From Dörr, I. 1997. How Striga parasitizes its host: a TEM and SEM study. Annals of Botany 79:463-472. Used with permission.
7. SEM of the inside of a Zea root vessel member (V) showing several Striga hermonthica oscula penetrating the pitted wall. Arrows point to the fibrillar wall structure around the parasite's penetration point. Bar = 2 µm. From Dörr, I. 1997. How Striga parasitizes its host: a TEM and SEM study. Annals of Botany 79:463-472. Used with permission.
8. Subterranean plantlets excavated, attached to host roots. Photo by L. J. Musselman.

S. hirsuta

1. Shoot with flowers. Mali. Photo by L. J. Musselman.

S. klingii

1. Shoot with flowers. Nigeria (LJM No. 5533). Photo by L. J. Musselman.

S. lutea

1. Shoot with flowers. Africa. Photo by L. J. Musselman.
2. Comparison of S. lutea (right, red flower form) & S. passargei (left). Africa. Photo by L. J. Musselman.

S. macrantha

1. Shoot with flowers. Nigeria (LJM No. 5532). Photo by L. J. Musselman.
   

S. passargei

1. Shoot with flowers. Burkina Faso. Photo by L. J. Musselman.

Striga Species Table

The genus Striga was recently monographed. See:

Mohamed, K.I., L.J. Musselman and C.R. Riches. 2001. The Genus Striga (Scrophulariaceae) in Africa. Annals of the Missouri Botanical Garden 88:60-103.

The following Table lists the species recognized in that publication.

	Striga Species	Authority	Distribution
1	S. aequinoctialis	Chev. Ex Hutch. & Dalz.	W. Africa
2	S. angolensis	K. I. Mohamed & L. J. Musselman	Angola
3	S. angustifolia	(Don) Saldanha	E. Africa, Asia, Indonesia
4	S. asiatica	(L.) Kuntz	Africa, Arabian peninsula, India, Burma, China, Indonesia, Philippines, Malaysia, New Guinea, Australia (?), USA (introduced)
5	S. aspera	(Willd.) Benth.	Africa
6	S. bilabiata	(Thunb.) O. Ktze.	Africa
	ssp. barteri	(Engl.) Heper
	ssp. bilabiata	Kuntze
	ssp. ledermannii	(Pilger) Hepper
	ssp. linearifolia	(Schum. & Thonn.) Mohamed
	ssp. rowlandii	(Engl. ) Hepper
7	S. brachycalyx	Sckan	Africa
8	S. chrysantha	A. Raynal	Central Africa
9	S. dalzielii	Hutch.	W. Africa
10	S. elegans	Benth.	Angola, Malawi, S. Africa, Zimbabwe
11	S. forbesii	Benth.	Africa, Madagascar
12	S. gastonii	A. Raynal	Chad and Central African Republic
13	S. gesnerioides	(Willd.) Vatke	Africa, Arabian peninsula, India, USA (introduced)
14	S. gracillima	Melch.	Tanzania
15	S. hallaei	A. Raynal	Gabon, Democratic Rebublic of Congo
16	S. hermonthica	(Del.) Benth.	Senegal to Ethiopia, Democratic Republic of Congo and Tanzania, Angola, Namibia
17	S. hirsuta	Benth.	Madagascar
18	S. junodii	Schinz	S. Africa, Mozambique
19	S. klingii	(Engl.) Skan	W. Africa, Nigeria, Ghana, Cameroon, Togo
20	S. latericea	Vatke	E. Africa, Ethiopia, Somalia
21	S. lepidagathidis	A. Raynal	Senegal, Guinea, Guinea Bissau.
22	S. lutea	Lour.	Sudan, Ethiopia
23	S. macrantha	(Benth.) Benth.	W. Africa, Nigeria, Ivory Coast, Togo
24	S. passargei	Engl.	W. & C. Africa, Arabian peninsula (?)
25	S. pinnatifida	Getachew	Ethiopia
26	S. primuloides	A. Chev.	Ivory Coast, Nigeria
27	S. pubiflora	Klotzsch	Somalia
28	S. yemenica	Musselman and Hepper	Ethiopia