Hypericum sect. Arthrophyllum, Jaub. & Spach

Fırat, Mehmet & Eroğlu, Hüseyin, 2023, Hypericum celikaensis (Hypericaceae), a new species from southeastern Anatolia (Adıyaman-Turkey), Candollea 78 (1), pp. 79-87 : 86

Key to the species of Hypericum sect. Arthrophyllum [adapted from ROBSON, 1996]

1. Sepals and bracts with marginal, reddish or black glands ..................................................................................... 2

1a. Sepals and bracts without marginal glands .................. 4

2. Leaves perfoliate ................................. H. pamphylicum

2a. Leaves free ................................................................... 3

3. Sepals base free, margin distally with 2–7 sessile black glands ...................................................... H. celikaensis

3a. Sepals base 0.3–0.5 of its length fused, margin distally with 14–22 sessile black glands .................... H. rupestre

4. Leaves (at least middle and upper) with base cordateamplexicaul; flowers numerous, in dense corymbiform cymes ................................................. H. cardiophyllum

4a. Leaves all with base cuneate to rounded; flowers 1–9, solitary or in lax corymbiform cymes ................................ 5

5. Sepals oblong to ovate, rounded to subacute at apex; leaves chartaceous, with venation prominent on both sides; flowers usually solitary ....................... H. vacciniifolium

5a. Sepals lanceolate, acute to shortly acuminate at apex; leaves subcoriaceous, with venation not or scarcely prominent; flowers usually 2–9 ............................................. 6

6. Stems erect, plant bushy; leaves ovate to broadly elliptic or orbicular; inner sepals triangular-lanceolate to narrowly oblong ........................................ H. nanum var. nanum

6a. Stems prostrate, plant appressed; leaves broadly to narrowly elliptic; inner sepals broadly ovate ........................ .............................................. H. nanum var. prostratum