Lepidium pumilum Boiss. & Balansa

AL-Shehbaz, Ihsan A. & Barriera, Gabrielle, 2019, Typification of Edmond Boissier’s Cruciferae (Brassicaceae) names enumerated in Flora Orientalis, Boissiera 72, pp. 1-193 : 151-152

Lepidium pumilum Boiss. & Balansa in Boiss., Diagn. Pl. Orient. ser. 2, 6: 21. 1859.

Type: “Hab. in salsis ad margines paludum ad occidentem Caesareae sitarum alt. 1000 metr. cl. Balansa qui legit fructiferam Sept. 1856 ”.

Holotypus: TURKEY: “Terrains salés. − Bords des marais situés à l’ouest de Césarée (Cappadoce)”, c. 1107 m, 23.VII.1856, Balansa 448 ( G-BOIS [ G00150395 ]; iso-: BM [ BM001172145 ], FI [ FI 005690], G [ G00446260 , G00446261 ], JE [ JE00005905 ], K [ K000642709 , K000642710 ], P [ P05444741 , P05444743 , P05444744 ], W [ W18890019374 , W18890069354 ], ZT [ ZT00078598 , ZT00078599 ]) ( Fig. 30 , p. 122) .

Notes. – The holotype has a handwritten label by Balansa with the field number 448. The labels of the isotypes have printed, handwritten label by Balansa “Prés salés situés au NO de Césarée (Cappadoce), à 1100 mètr. d’alt.” with the exsiccatae number 999.

This and the previous three entries belong to the Lepidium cartilagineum complex in which a total of 20 species and infraspecific taxa have been described by various authors. No single treatment has been satisfactory, and thorough molecular phylogenetic studies, coupled with a critical re-evaluation of morphology in light of molecular data, are needed to determine the status of every specific and infraspecific taxon recognized in this complex. THELLUNG (1906b) provided the latest and most comprehensive treatment of the complex, and he divided L. cartilagineum into two subspecies, of which only subsp. cartilagineum was further divided into five varieties and four forms.

Lepidium cartilagineum subsp. caespitosum (Desv.) Thell. is by far the most distinctive, and it differs from subsp. cartilagineum by having caudex branches densely covered with leaf remains of previous seasons (vs naked caudices), narrowly linear to filiform (vs suborbicular, broadly ovate, elliptic, or lanceolate) basal leaves, non-auriculate, linear (vs frequently auriculate, variously shaped) cauline leaves, sepals 2.5–3 (vs 1–1.5) mm long, and fruit 4 –5 (vs 2–3.5) mm long. In our opinion, these are well-defined taxa, and L. caespitosum Desv. ought to be maintained as a distinct species.

The rest of the complex was treated by THELLUNG (1906b) as Lepidium cartilagineum subsp. crassifolium (Waldst. & Kit.) Thell. , and it included the type of L. cartilagineum . Therefore, it should be recognized it as subsp. cartilagineum , just as more recently done by HEDGE (1968: 67), but not as HEDGE (1965: 283), where he followed Thellung.

In addition to the variation in basal- and cauline-leaf morphology and development of auricles on uppermost cauline leaves, plants of this complex can be quite variable in height and the degree of branching, and only three taxa are consistently recognizable here. The subsp. cartilagineum is the most widespread (Asian Turkey, Caucasus, W Russia, Iran, Afghanistan, Pakistan), and the bulk of its range falls within the Flora Orientalis area. It consists of robust plants often (15–) 18–35 cm tall, entire, or rarely obscurely dentate and basally cuneate basal leaves, and sagittate to amplexicaul or cordate upper cauline leaves.

By contrast, subsp. crenatifolium (endemic to central Turkey) has orbicular to broadly ovate basal leaves with truncate base and prominently crenate margin, and rather small cauline leaves with poorly developed auricles. Boissier in Flora Orientalis maintained this taxon as a distinct species, THELLUNG (1906b) reduced it to a variety of L. cartilagineum , and it is maintained here as a subspecies of the latter species. Finally, L. pumilum (Crimea, central Turkey, Iran) is a small plant 6–12(–15) cm tall, with lanceolate, entire, and basally cuneate to attenuate basal leaves, and narrowly lanceolate to linear and exauriculate or very rarely minutely auriculate uppermost cauline leaves. It can easily be distinguished from the other members of the L. cartilagineum complex, and Boissier in Flora Orientalis is followed in recognizing it as a distinct species.

By contrast, THELLUNG (1906b) treated L. pumilum as a variety of L. cartilagineum subsp. crassifolium (Waldst. & Kit.) Thell., HEDGE (1965) reduced it to synonymy of subsp. cartilagineum , and then HEDGE (1968) and BRASSIBASE (2019) accepted it as L. cartilagineum subsp. pumilum (Boiss. & Balansa) Hedge.

Figures

Fig.30. Holotype of Lepidium pumilum Boiss. & Balansa in G-BOIS (p.151).