Thurber's desert honeysuckle, more...
[Anisacanthus siphoglossa (Torr.) A. Gray, more]
Acanthaceae of Sonora: Taxonomy and Phytogeography Thomas F. Daniel: Shrubs to 1.5 (–3) m tall. Young stems subquadrate, evenly pubescent with an understory of erect subglandular and eglandular trichomes 0.05–0.2 mm long and sometimes with a bifariously disposed overstory of scattered to dense erect to flexuose eglandular trichomes 0.2–1 mm long, soon becoming bifariously pubescent with flexuose to retrorse to retrorsely appressed eglandular trichomes to 1 mm long (hirsute), nodes often hirsute, epidermis of older stems exfoliating in papery strips. Leaves (plants often leafless during anthesis), petiolate, petioles to 7 (–14) mm long, blades narrowly lanceolate to lanceolate to ovate, 11–50 (–65) mm long, (2–) 4–14.5 (–35) mm wide, 3.8–5.6 (–13) times longer than wide, (acute to) acuminate at apex, (rounded to) acute at base, surfaces pubescent with flexuose to antrorse eglandular trichomes to 0.5 mm long. Inflorescence of axillary or terminal dichasiate racemes to 3 cm long, axillary racemes usually borne at nodes of older woody stems and often condensed (i.e., lacking a prominent rachis) and appearing as an axillary cluster of subfoliose bracts and flowers, rachis pubescent like young stems; dichasia 1 (or more)-flowered, opposite, sessile in axils of distal reduced leaves or subfoliose bracts, 1 or more per axil. Bracts sometimes caducous, subfoliose, linear-lanceolate to lance-ovate to elliptic to obovate, (6.5–) 8–28 mm long 1–8.5 mm wide, abaxial surface pubescent like rachis, several pairs of smaller sterile and closely imbricate bracts sometimes present at base of inflorescence. Bracteoles sometimes caducous, linear-lanceolate to linear to linear-elliptic to oblanceolate, (2–) 4–12 (–20) mm long, 0.5–2.5 mm wide, abaxial surface pubescent like bracts. Flowers pedicellate, pedicels 2–10 mm long, pubescent like young stems and also with conspicuous glandular trichomes to 0.3 mm long. Calyx 6.5–14 mm long during anthesis (accrescent and up to 16 mm long in fruit), lobes subulate, 4.5–13 mm long, abaxially pubescent like pedicels. Corolla orange (or sometimes dull reddish), (25–) 30–43 mm long, externally pubescent with erect to flexuose eglandular trichomes 0.1–0.3 mm long, tube (13–) 17–22 mm long, upper lip recurved, strap shaped, 10–22 mm long, entire to 2-lobed at apex, lobes to 0.3 mm long, lower lip 11–21 mm long, lobes often recurved or recoiled, linear, homomorphic, 10–17 mm long. Stamens 19–35 mm long, filaments glabrous, thecae red, 3–4 mm long. Style white, (26–) 28–44 mm long, glabrous, stigma lobes 0.2–0.3 mm long. Capsule 12–17 mm long, glabrous, stipe 5–7 mm long, head 7–11 mm long. Seeds 4.8–7 mm long, 4.4–5.8 mm wide, surfaces smooth to rugose. (n = 18). Plant: Shrub to 1.5 m Leaves: leaves opposite, lanceolate 1-3 cm long Flowers: flowers showy, orange, tubular and bilabiate Fruit: an explosive capsule that splits in two.