Orthocarpus
Gen. N. Amer. Pl. 2: 56. 1818.
| Taxon | Illustrator ⠉ | |
|---|---|---|
 | Dicranostegia orcuttiana Orthocarpus luteus Triphysaria eriantha subsp. eriantha | John Myers Barbara Alongi Barbara Alongi |
Herbs, annual; hemiparasitic. Stems erect or ascending, not fleshy, glabrous or hairy. Leaves cauline, alternate; petiole absent; blade not fleshy, not leathery, margins entire or 3–7-lobed. Inflorescences terminal, spikes or racemes; bracts present. Pedicels absent or present; bracteoles absent. Flowers: sepals 4, calyx symmetric, tubular, lobes triangular; petals 5, corolla purple-pink, yellow, or white, strongly bilabiate, club-shaped, often gibbous at base of abaxial lip, abaxial lobes 0 or 3, adaxial 2, adaxial lip galeate, rounded at apex, sometimes obscurely so, opening downward; stamens 4, didynamous, filaments glabrous or hairy; staminode 0; ovary 2-locular, placentation axile; stigma linear, not expanded at apex. Capsules: dehiscence loculicidal. Seeds 5–35, light to dark-brown or yellow, ovoid to reniform or oblong, wings absent. x = 7.
Distribution
w North America
Discussion
Species 9 (9 in the flora).
Orthocarpus is related to Cordylanthus and can be distinguished by its four-lobed, tubular calyces (D. C. Tank et al. 2009). Some species placed traditionally in Orthocarpus were transferred to Castilleja and Triphysaria by T. I. Chuang and L. R. Heckard (1991).
Selected References
Lower Taxa
Key
| 1 | Bract margins 5–7-lobed; pedicels 2–3 mm; corollas: adaxial lips bearded at tip. | Orthocarpus barbatus |
| 1 | Bract margins entire or 3(–5)-lobed; pedicels 0–2 mm; corollas: adaxial lips not bearded at tip. | > 2 |
| 2 | Bracts: midlobes ovate or obovate, 4–10 mm wide, apices obtuse, cuspidate. | > 3 |
| 3 | Corollas: adaxial lips not hooked at tip. | Orthocarpus cuspidatus |
| 3 | Corollas: adaxial lips notably hooked at tip. | > 4 |
| 4 | Corollas 25–30 mm, adaxial lips glabrous, abaxial lobes rounded. | Orthocarpus pachystachyus |
| 4 | Corollas 10–20 mm, adaxial lips puberulent, abaxial lobes triangular. | > 5 |
| 5 | Distal leaf margins entire; calyces 5–7 mm; capsules 4–5 mm, apices retuse. | Orthocarpus imbricatus |
| 5 | Distal leaf margins 3–7 lobed; calyces 8–12 mm; capsules 6–7 mm, apices acute. | Orthocarpus tenuifolius |
| 2 | Bracts: midlobes triangular, 0.7–4 mm wide, apices acute or acuminate, not cuspidate. | > 6 |
| 6 | Corollas: adaxial lips golden yellow, tips minutely hooked. | Orthocarpus luteus |
| 6 | Corollas: adaxial lips yellow or purple-pink to white, tips notably hooked. | > 7 |
| 7 | Distal leaf margins entire; seeds 3–6; corollas: abaxial lips with triangular lobes. | Orthocarpus tolmiei |
| 7 | Distal leaf margins 3-lobed; seeds 10–26; corollas: abaxial lips with lobes 0. | > 8 |
| 8 | Bracts: midlobes 3–4 mm wide, lateral lobes narrowly triangular; capsule apices retuse; seeds 10–15. | Orthocarpus bracteosus |
| 8 | Bracts: midlobes 1–2 mm wide, lateral lobes linear; capsule apices cuspidate; seeds 18–26. | Orthocarpus purpureoalbus |